diff --git a/tests/integration/includes/http/MWHttpRequestTestCase.php b/tests/integration/includes/http/MWHttpRequestTestCase.php
index cbaa8f9b9bc..ec6dd45d36c 100644
--- a/tests/integration/includes/http/MWHttpRequestTestCase.php
+++ b/tests/integration/includes/http/MWHttpRequestTestCase.php
@@ -170,7 +170,7 @@ abstract class MWHttpRequestTestCase extends PHPUnit\Framework\TestCase {
 
 		$request = $this->factory->create( 'http://httpbin.org/ip' );
 		$data = '';
-		$request->setCallback( function ( $fh, $content ) use ( &$data ) {
+		$request->setCallback( static function ( $fh, $content ) use ( &$data ) {
 			$data .= $content;
 			return strlen( $content );
 		} );
diff --git a/tests/parser/ParserTestRunner.php b/tests/parser/ParserTestRunner.php
index 6d2856df492..5daf6c4b112 100644
--- a/tests/parser/ParserTestRunner.php
+++ b/tests/parser/ParserTestRunner.php
@@ -375,7 +375,7 @@ class ParserTestRunner {
 		MediaWikiServices::getInstance()->disableService( 'MediaHandlerFactory' );
 		MediaWikiServices::getInstance()->redefineService(
 			'MediaHandlerFactory',
-			function ( MediaWikiServices $services ) {
+			static function ( MediaWikiServices $services ) {
 				$handlers = $services->getMainConfig()->get( 'ParserTestMediaHandlers' );
 				return new MediaHandlerFactory( $handlers );
 			}
@@ -877,7 +877,7 @@ class ParserTestRunner {
 
 			$oldCallback = $options->getCurrentRevisionRecordCallback();
 			$options->setCurrentRevisionRecordCallback(
-				function ( Title $t, $parser = null ) use ( $title, $revRecord, $oldCallback ) {
+				static function ( Title $t, $parser = null ) use ( $title, $revRecord, $oldCallback ) {
 					if ( $t->equals( $title ) ) {
 						return $revRecord;
 					} else {
@@ -938,7 +938,7 @@ class ParserTestRunner {
 		$teardownGuard = $this->perTestSetup( $test );
 		[ $title, $options, $revId ] = $this->setupParserOptions(
 			(object)$test,
-			function ( $context, $title, $revId, $wikitext ) {
+			static function ( $context, $title, $revId, $wikitext ) {
 				return ParserOptions::newFromContext( $context );
 			}
 		);
@@ -949,12 +949,12 @@ class ParserTestRunner {
 		if ( isset( $opts['styletag'] ) ) {
 			// For testing the behavior of <style> (including those deduplicated
 			// into <link> tags), add tag hooks to allow them to be generated.
-			$parser->setHook( 'style', function ( $content, $attributes, $parser ) {
+			$parser->setHook( 'style', static function ( $content, $attributes, $parser ) {
 				$marker = Parser::MARKER_PREFIX . '-style-' . md5( $content ) . Parser::MARKER_SUFFIX;
 				$parser->mStripState->addNoWiki( $marker, $content );
 				return Html::inlineStyle( $marker, 'all', $attributes );
 			} );
-			$parser->setHook( 'link', function ( $content, $attributes, $parser ) {
+			$parser->setHook( 'link', static function ( $content, $attributes, $parser ) {
 				return Html::element( 'link', $attributes );
 			} );
 		}
@@ -1106,7 +1106,7 @@ class ParserTestRunner {
 		$teardownGuard = $this->perTestSetup( $test );
 		[ $title, $options, $revId ] = $this->setupParserOptions(
 			$test,
-			function ( $context, $title, $revId, $wikitext ) use ( $pageConfigFactory, &$pageConfig ) {
+			static function ( $context, $title, $revId, $wikitext ) use ( $pageConfigFactory, &$pageConfig ) {
 				$pageConfig = $pageConfigFactory->create(
 					$title,
 					$context->getUser(),
@@ -1256,7 +1256,7 @@ class ParserTestRunner {
 			MediaWikiServices::getInstance()->disableService( 'ContentLanguage' );
 			MediaWikiServices::getInstance()->redefineService(
 				'ContentLanguage',
-				function () use ( $lang ) {
+				static function () use ( $lang ) {
 					return $lang;
 				}
 			);
@@ -1711,7 +1711,7 @@ class ParserTestRunner {
 			$setup[] = static function () use ( $lang ) {
 				$services = MediaWikiServices::getInstance();
 				$services->disableService( 'ContentLanguage' );
-				$services->redefineService( 'ContentLanguage', function () use ( $lang ) {
+				$services->redefineService( 'ContentLanguage', static function () use ( $lang ) {
 					return $lang;
 				} );
 			};
diff --git a/tests/parser/TestFileReader.php b/tests/parser/TestFileReader.php
index c35dae770f8..8c7e422ce56 100644
--- a/tests/parser/TestFileReader.php
+++ b/tests/parser/TestFileReader.php
@@ -37,7 +37,7 @@ class TestFileReader {
 		if ( isset( $options['regex'] ) ) {
 			$options['filter'] = [ 'regex' => $options['regex'] ];
 		}
-		$parsoidReader = ParsoidTestFileReader::read( $file, function ( $msg ) {
+		$parsoidReader = ParsoidTestFileReader::read( $file, static function ( $msg ) {
 			wfDeprecatedMsg( $msg, '1.35', false, false );
 		} );
 		$testFormat = intval( $parsoidReader->fileOptions['version'] ?? '1' );
diff --git a/tests/parser/editTests.php b/tests/parser/editTests.php
index bdf9e4d01b4..1d94d348071 100644
--- a/tests/parser/editTests.php
+++ b/tests/parser/editTests.php
@@ -409,7 +409,7 @@ class ParserEditTests extends Maintenance {
 			return false;
 		}
 		$result = TestFileEditor::edit( $text, $deletions, $changes,
-			function ( $msg ) {
+			static function ( $msg ) {
 				print "$msg\n";
 			}
 		);
diff --git a/tests/parser/parserTests.php b/tests/parser/parserTests.php
index 111721b86f0..88e34e1eeb9 100644
--- a/tests/parser/parserTests.php
+++ b/tests/parser/parserTests.php
@@ -160,7 +160,7 @@ class ParserTestsMaintenance extends Maintenance {
 			}
 			$recorder->addRecorder( new DbTestPreviewer(
 				$recorderDB,
-				function ( $name ) use ( $regex ) {
+				static function ( $name ) use ( $regex ) {
 					// Filter reports of old tests by the filter regex
 					if ( $regex === false ) {
 						return true;
diff --git a/tests/phpunit/MediaWikiIntegrationTestCase.php b/tests/phpunit/MediaWikiIntegrationTestCase.php
index a81ec9c218d..e512930fb51 100644
--- a/tests/phpunit/MediaWikiIntegrationTestCase.php
+++ b/tests/phpunit/MediaWikiIntegrationTestCase.php
@@ -582,7 +582,7 @@ abstract class MediaWikiIntegrationTestCase extends PHPUnit\Framework\TestCase {
 
 		// T46192 Do not attempt to send a real e-mail
 		$this->setTemporaryHook( 'AlternateUserMailer',
-			function () {
+			static function () {
 				return false;
 			}
 		);
@@ -1079,7 +1079,7 @@ abstract class MediaWikiIntegrationTestCase extends PHPUnit\Framework\TestCase {
 		$newServices->resetServiceForTesting( 'DBLoadBalancerFactory' );
 		$newServices->redefineService(
 			'DBLoadBalancerFactory',
-			function ( MediaWikiServices $services ) use ( $oldLoadBalancerFactory ) {
+			static function ( MediaWikiServices $services ) use ( $oldLoadBalancerFactory ) {
 				return $oldLoadBalancerFactory;
 			}
 		);
@@ -1088,7 +1088,7 @@ abstract class MediaWikiIntegrationTestCase extends PHPUnit\Framework\TestCase {
 		$newServices->resetServiceForTesting( 'HttpRequestFactory' );
 		$newServices->redefineService(
 			'HttpRequestFactory',
-			function ( MediaWikiServices $services ) {
+			static function ( MediaWikiServices $services ) {
 				return new NullHttpRequestFactory();
 			}
 		);
@@ -1139,7 +1139,7 @@ abstract class MediaWikiIntegrationTestCase extends PHPUnit\Framework\TestCase {
 		global $wgParser, $wgContLang;
 		// We don't have to replace the parser if it wasn't unstubbed
 		if ( !( $wgParser instanceof StubObject ) ) {
-			$wgParser = new StubObject( 'wgParser', function () {
+			$wgParser = new StubObject( 'wgParser', static function () {
 				return MediaWikiServices::getInstance()->getParser();
 			} );
 		}
diff --git a/tests/phpunit/includes/ActorMigrationTest.php b/tests/phpunit/includes/ActorMigrationTest.php
index 8e08ef9de78..9f8610d3d1b 100644
--- a/tests/phpunit/includes/ActorMigrationTest.php
+++ b/tests/phpunit/includes/ActorMigrationTest.php
@@ -30,7 +30,7 @@ class ActorMigrationTest extends MediaWikiLangTestCase {
 			'removed' => $w->removed,
 			'specialFields' => $w->specialFields,
 		];
-		$this->resetActorMigration = new ScopedCallback( function ( $w, $data ) {
+		$this->resetActorMigration = new ScopedCallback( static function ( $w, $data ) {
 			foreach ( $data as $k => $v ) {
 				$w->$k = $v;
 			}
diff --git a/tests/phpunit/includes/DeprecatedGlobalTest.php b/tests/phpunit/includes/DeprecatedGlobalTest.php
index 5f2cbcd1c05..3904d65d9e3 100644
--- a/tests/phpunit/includes/DeprecatedGlobalTest.php
+++ b/tests/phpunit/includes/DeprecatedGlobalTest.php
@@ -51,7 +51,7 @@ class DeprecatedGlobalTest extends MediaWikiIntegrationTestCase {
 		global $wgDummyLazy;
 
 		$called = false;
-		$factory = function () use ( &$called ) {
+		$factory = static function () use ( &$called ) {
 			$called = true;
 			return new HashBagOStuff();
 		};
diff --git a/tests/phpunit/includes/EditPageConstraintsTest.php b/tests/phpunit/includes/EditPageConstraintsTest.php
index 7319bccb9f2..fe94e9b1f38 100644
--- a/tests/phpunit/includes/EditPageConstraintsTest.php
+++ b/tests/phpunit/includes/EditPageConstraintsTest.php
@@ -363,7 +363,7 @@ class EditPageConstraintsTest extends MediaWikiLangTestCase {
 	) {
 		$this->setTemporaryHook(
 			'EditFilterMergedContent',
-			function ( $context, $content, $status, $summary, $user, $minorEdit )
+			static function ( $context, $content, $status, $summary, $user, $minorEdit )
 				use ( $hookReturn, $statusValue, $statusFatal )
 			{
 				if ( $statusValue !== null ) {
@@ -700,7 +700,7 @@ class EditPageConstraintsTest extends MediaWikiLangTestCase {
 	public function testUserRateLimitConstraint() {
 		$this->setTemporaryHook(
 			'PingLimiter',
-			function ( $user, $action, &$result, $incrBy ) {
+			static function ( $user, $action, &$result, $incrBy ) {
 				// Always fail
 				$result = true;
 				return false;
diff --git a/tests/phpunit/includes/EditPageTest.php b/tests/phpunit/includes/EditPageTest.php
index aee6036faa1..7dbd4510bd1 100644
--- a/tests/phpunit/includes/EditPageTest.php
+++ b/tests/phpunit/includes/EditPageTest.php
@@ -456,7 +456,7 @@ class EditPageTest extends MediaWikiLangTestCase {
 
 		$checkIds = [];
 		$this->setMwGlobals( 'wgHooks', [
-			'PageContentSaveComplete' => [ function (
+			'PageContentSaveComplete' => [ static function (
 				WikiPage &$page, User &$user, Content $content,
 				$summary, $minor, $u1, $u2, &$flags, Revision $revision,
 				Status &$status, $baseRevId
@@ -836,7 +836,7 @@ hello
 	/** @covers EditPage */
 	public function testShouldPreventChangingContentModelWhenUserCannotChangeModelForTitle() {
 		$this->setTemporaryHook( 'getUserPermissionsErrors',
-			function ( Title $page, $user, $action, &$result ) {
+			static function ( Title $page, $user, $action, &$result ) {
 				if ( $action === 'editcontentmodel' &&
 					 $page->getContentModel() === CONTENT_MODEL_WIKITEXT ) {
 					$result = false;
@@ -865,7 +865,7 @@ hello
 	/** @covers EditPage */
 	public function testShouldPreventChangingContentModelWhenUserCannotEditTargetTitle() {
 		$this->setTemporaryHook( 'getUserPermissionsErrors',
-			function ( Title $page, $user, $action, &$result ) {
+			static function ( Title $page, $user, $action, &$result ) {
 				if ( $action === 'edit' && $page->getContentModel() === CONTENT_MODEL_WIKITEXT ) {
 					$result = false;
 					return false;
diff --git a/tests/phpunit/includes/HookContainer/HookContainerIntegrationTest.php b/tests/phpunit/includes/HookContainer/HookContainerIntegrationTest.php
index 0344d7a87aa..9a68297619f 100644
--- a/tests/phpunit/includes/HookContainer/HookContainerIntegrationTest.php
+++ b/tests/phpunit/includes/HookContainer/HookContainerIntegrationTest.php
@@ -36,17 +36,17 @@ namespace MediaWiki\HookContainer {
 			$hookContainer = MediaWikiServices::getInstance()->getHookContainer();
 
 			// Some handlers for FooHook have been previously set
-			$reset = $hookContainer->register( 'FooHook', function () {
+			$reset = $hookContainer->register( 'FooHook', static function () {
 				return true;
 			} );
-			$reset1 = $hookContainer->register( 'FooHook', function () {
+			$reset1 = $hookContainer->register( 'FooHook', static function () {
 				return true;
 			} );
 			$handlersBeforeScopedRegister = $hookContainer->getLegacyHandlers( 'FooHook' );
 			$this->assertCount( 2, $handlersBeforeScopedRegister );
 
 			// Wipe out the 2 existing handlers and add a new scoped handler
-			$reset2 = $hookContainer->scopedRegister( 'FooHook', function () {
+			$reset2 = $hookContainer->scopedRegister( 'FooHook', static function () {
 				return true;
 			}, true );
 			$handlersAfterScopedRegister = $hookContainer->getLegacyHandlers( 'FooHook' );
@@ -68,10 +68,10 @@ namespace MediaWiki\HookContainer {
 		public function testHookRunsWithMultipleMixedHandlerTypes() {
 			$hookContainer = MediaWikiServices::getInstance()->getHookContainer();
 			$numHandlersExecuted = 0;
-			$reset = $hookContainer->scopedRegister( 'FooHook', function ( &$numHandlersRun ) {
+			$reset = $hookContainer->scopedRegister( 'FooHook', static function ( &$numHandlersRun ) {
 				$numHandlersRun++;
 			}, false );
-			$reset2 = $hookContainer->scopedRegister( 'FooHook', function ( &$numHandlersRun ) {
+			$reset2 = $hookContainer->scopedRegister( 'FooHook', static function ( &$numHandlersRun ) {
 				$numHandlersRun++;
 			}, false );
 			$handlerThree = [
diff --git a/tests/phpunit/includes/HooksTest.php b/tests/phpunit/includes/HooksTest.php
index 055e624e6c8..b9d53ddcf34 100644
--- a/tests/phpunit/includes/HooksTest.php
+++ b/tests/phpunit/includes/HooksTest.php
@@ -43,12 +43,12 @@ class HooksTest extends MediaWikiIntegrationTestCase {
 			],
 			[ 'Global function', [ 'NothingFunction' ], 'changed-func', 'original' ],
 			[ 'Global function with data', [ 'NothingFunctionData', 'data' ], 'data', 'original' ],
-			[ 'Closure', [ function ( &$foo, $bar ) {
+			[ 'Closure', [ static function ( &$foo, $bar ) {
 				$foo = 'changed-closure';
 
 				return true;
 			} ], 'changed-closure', 'original' ],
-			[ 'Closure with data', [ function ( $data, &$foo, $bar ) {
+			[ 'Closure with data', [ static function ( $data, &$foo, $bar ) {
 				$foo = $data;
 
 				return true;
@@ -166,10 +166,10 @@ class HooksTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testFalseReturn() {
 		$hookContainer = MediaWikiServices::getInstance()->getHookContainer();
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$foo ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$foo ) {
 			return false;
 		} );
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$foo ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$foo ) {
 			$foo = 'test';
 			return true;
 		} );
@@ -183,10 +183,10 @@ class HooksTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testNullReturn() {
 		$hookContainer = MediaWikiServices::getInstance()->getHookContainer();
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$foo ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$foo ) {
 			return;
 		} );
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$foo ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$foo ) {
 			$foo = 'test';
 
 			return true;
@@ -202,7 +202,7 @@ class HooksTest extends MediaWikiIntegrationTestCase {
 	public function testCallHook_FalseHook() {
 		$hookContainer = MediaWikiServices::getInstance()->getHookContainer();
 		$hookContainer->register( 'MediaWikiHooksTest001', false );
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$foo ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$foo ) {
 			$foo = 'test';
 
 			return true;
@@ -238,15 +238,15 @@ class HooksTest extends MediaWikiIntegrationTestCase {
 	public function testRunWithoutAbort() {
 		$list = [];
 		$hookContainer = MediaWikiServices::getInstance()->getHookContainer();
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$list ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$list ) {
 			$list[] = 1;
 			return true; // Explicit true
 		} );
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$list ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$list ) {
 			$list[] = 2;
 			return; // Implicit null
 		} );
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$list ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$list ) {
 			$list[] = 3;
 			// No return
 		} );
@@ -260,10 +260,10 @@ class HooksTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testRunWithoutAbortWarning() {
 		$hookContainer = MediaWikiServices::getInstance()->getHookContainer();
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$foo ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$foo ) {
 			return false;
 		} );
-		$hookContainer->register( 'MediaWikiHooksTest001', function ( &$foo ) {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function ( &$foo ) {
 			$foo = 'test';
 			return true;
 		} );
@@ -281,7 +281,7 @@ class HooksTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testFatalError() {
 		$hookContainer = MediaWikiServices::getInstance()->getHookContainer();
-		$hookContainer->register( 'MediaWikiHooksTest001', function () {
+		$hookContainer->register( 'MediaWikiHooksTest001', static function () {
 			return 'test';
 		} );
 		$this->expectDeprecation();
diff --git a/tests/phpunit/includes/ListToggleTest.php b/tests/phpunit/includes/ListToggleTest.php
index 86a74930e32..11af2d05c79 100644
--- a/tests/phpunit/includes/ListToggleTest.php
+++ b/tests/phpunit/includes/ListToggleTest.php
@@ -30,7 +30,7 @@ class ListToggleTest extends MediaWikiIntegrationTestCase {
 		$output = $this->createMock( OutputPage::class );
 		$output->expects( $this->any() )
 			->method( 'msg' )
-			->will( $this->returnCallback( function ( $key ) {
+			->will( $this->returnCallback( static function ( $key ) {
 				return wfMessage( $key )->inLanguage( 'qqx' );
 			} ) );
 		$output->expects( $this->once() )
diff --git a/tests/phpunit/includes/MediaWikiServicesTest.php b/tests/phpunit/includes/MediaWikiServicesTest.php
index 7e2ed62a3c4..42b077971f4 100644
--- a/tests/phpunit/includes/MediaWikiServicesTest.php
+++ b/tests/phpunit/includes/MediaWikiServicesTest.php
@@ -80,7 +80,7 @@ class MediaWikiServicesTest extends MediaWikiIntegrationTestCase {
 
 		$newServices->defineService(
 			'Test',
-			function () use ( $service1 ) {
+			static function () use ( $service1 ) {
 				return $service1;
 			}
 		);
@@ -124,7 +124,7 @@ class MediaWikiServicesTest extends MediaWikiIntegrationTestCase {
 
 		$newServices->defineService(
 			'Test',
-			function () use ( &$instantiatorReturnValues ) {
+			static function () use ( &$instantiatorReturnValues ) {
 				return array_shift( $instantiatorReturnValues );
 			}
 		);
@@ -156,7 +156,7 @@ class MediaWikiServicesTest extends MediaWikiIntegrationTestCase {
 								[
 									'handler' => [
 										'name' => 'test',
-										'factory' => function () {
+										'factory' => static function () {
 											return new class implements MediaWikiServicesHook {
 												public function onMediaWikiServices( $services ) {
 												}
@@ -195,7 +195,7 @@ class MediaWikiServicesTest extends MediaWikiIntegrationTestCase {
 
 		$newServices->redefineService(
 			'DBLoadBalancerFactory',
-			function () use ( $lbFactory ) {
+			static function () use ( $lbFactory ) {
 				return $lbFactory;
 			}
 		);
@@ -242,7 +242,7 @@ class MediaWikiServicesTest extends MediaWikiIntegrationTestCase {
 
 		$newServices->defineService(
 			'Test',
-			function () use ( &$instantiatorReturnValues ) {
+			static function () use ( &$instantiatorReturnValues ) {
 				return array_shift( $instantiatorReturnValues );
 			}
 		);
diff --git a/tests/phpunit/includes/MediaWikiTest.php b/tests/phpunit/includes/MediaWikiTest.php
index 14075070355..55542b375b5 100644
--- a/tests/phpunit/includes/MediaWikiTest.php
+++ b/tests/phpunit/includes/MediaWikiTest.php
@@ -197,14 +197,14 @@ class MediaWikiTest extends MediaWikiIntegrationTestCase {
 
 		// A job that attempts to set a cookie
 		$jobHasRun = false;
-		DeferredUpdates::addCallableUpdate( function () use ( $response, &$jobHasRun ) {
+		DeferredUpdates::addCallableUpdate( static function () use ( $response, &$jobHasRun ) {
 			$jobHasRun = true;
 			$response->setCookie( 'JobCookie', 'yes' );
 			$response->header( 'Foo: baz' );
 		} );
 
 		$hookWasRun = false;
-		$this->setTemporaryHook( 'WebResponseSetCookie', function () use ( &$hookWasRun ) {
+		$this->setTemporaryHook( 'WebResponseSetCookie', static function () use ( &$hookWasRun ) {
 			$hookWasRun = true;
 			return true;
 		} );
diff --git a/tests/phpunit/includes/Message/TextFormatterTest.php b/tests/phpunit/includes/Message/TextFormatterTest.php
index 6d1aa6f18fe..5e9c744f0d1 100644
--- a/tests/phpunit/includes/Message/TextFormatterTest.php
+++ b/tests/phpunit/includes/Message/TextFormatterTest.php
@@ -33,7 +33,7 @@ class TextFormatterTest extends MediaWikiIntegrationTestCase {
 					->getMock();
 
 				$message->method( 'fetchMessage' )
-					->willReturnCallback( function () use ( $message, $includeWikitext ) {
+					->willReturnCallback( static function () use ( $message, $includeWikitext ) {
 						/** @var Message $message */
 						$result = "{$message->getKey()} $1 $2";
 						if ( $includeWikitext ) {
diff --git a/tests/phpunit/includes/MovePageTest.php b/tests/phpunit/includes/MovePageTest.php
index 0aac1696e7b..260b56a278f 100644
--- a/tests/phpunit/includes/MovePageTest.php
+++ b/tests/phpunit/includes/MovePageTest.php
@@ -33,7 +33,7 @@ class MovePageTest extends MediaWikiIntegrationTestCase {
 
 		$mockLocalRepo = $this->createMock( LocalRepo::class );
 		$mockLocalRepo->method( 'newFile' )->will( $this->returnCallback(
-			function ( Title $title ) use ( $mockExistentFile, $mockNonexistentFile ) {
+			static function ( Title $title ) use ( $mockExistentFile, $mockNonexistentFile ) {
 				if ( in_array( $title->getPrefixedText(),
 					[ 'File:Existent.jpg', 'File:Existent2.jpg', 'File:Existent-file-no-page.jpg' ]
 				) ) {
@@ -70,7 +70,7 @@ class MovePageTest extends MediaWikiIntegrationTestCase {
 
 		$mockNsInfo = $this->createMock( NamespaceInfo::class );
 		$mockNsInfo->method( 'isMovable' )->will( $this->returnCallback(
-			function ( $ns ) {
+			static function ( $ns ) {
 				return $ns >= 0;
 			}
 		) );
@@ -118,7 +118,7 @@ class MovePageTest extends MediaWikiIntegrationTestCase {
 
 		// Set a couple of hooks for specific pages
 		$this->setTemporaryHook( 'ContentModelCanBeUsedOn',
-			function ( $modelId, Title $title, &$ok ) {
+			static function ( $modelId, Title $title, &$ok ) {
 				if ( $title->getPrefixedText() === 'No content allowed' ) {
 					$ok = false;
 				}
@@ -126,7 +126,7 @@ class MovePageTest extends MediaWikiIntegrationTestCase {
 		);
 
 		$this->setTemporaryHook( 'TitleIsMovable',
-			function ( Title $title, &$result ) {
+			static function ( Title $title, &$result ) {
 				if ( strtolower( $title->getPrefixedText() ) === 'hooked in place' ) {
 					$result = false;
 				}
@@ -373,7 +373,7 @@ class MovePageTest extends MediaWikiIntegrationTestCase {
 	public function testMoveAbortedByTitleMoveHook() {
 		$error = 'Preventing move operation with TitleMove hook.';
 		$this->setTemporaryHook( 'TitleMove',
-			function ( $old, $new, $user, $reason, $status ) use ( $error ) {
+			static function ( $old, $new, $user, $reason, $status ) use ( $error ) {
 				$status->fatal( $error );
 			}
 		);
diff --git a/tests/phpunit/includes/MultiHttpClientTest.php b/tests/phpunit/includes/MultiHttpClientTest.php
index 7609d48a98c..c6dc5dca8e7 100644
--- a/tests/phpunit/includes/MultiHttpClientTest.php
+++ b/tests/phpunit/includes/MultiHttpClientTest.php
@@ -260,7 +260,7 @@ class MultiHttpClientTest extends MediaWikiIntegrationTestCase {
 			->with(
 				$url,
 				$this->callback(
-					function ( $options ) use ( $expectedReqTimeout, $expectedConnTimeout ) {
+					static function ( $options ) use ( $expectedReqTimeout, $expectedConnTimeout ) {
 						return $options['timeout'] === $expectedReqTimeout
 							&& $options['connectTimeout'] === $expectedConnTimeout;
 					}
diff --git a/tests/phpunit/includes/OutputPageTest.php b/tests/phpunit/includes/OutputPageTest.php
index 3899e5e3609..2b09cafa237 100644
--- a/tests/phpunit/includes/OutputPageTest.php
+++ b/tests/phpunit/includes/OutputPageTest.php
@@ -528,18 +528,18 @@ class OutputPageTest extends MediaWikiIntegrationTestCase {
 					[ 'UseCdn' => true, 'CdnMaxAge' => 3599 ] ],
 			'Hook allows cache use' =>
 				[ $lastModified + 1, $lastModified, true, [],
-				function ( $op, $that ) {
+				static function ( $op, $that ) {
 					$that->setTemporaryHook( 'OutputPageCheckLastModified',
-						function ( &$modifiedTimes ) {
+						static function ( &$modifiedTimes ) {
 							$modifiedTimes = [ 1 ];
 						}
 					);
 				} ],
 			'Hooks prohibits cache use' =>
 				[ $lastModified, $lastModified, false, [],
-				function ( $op, $that ) {
+				static function ( $op, $that ) {
 					$that->setTemporaryHook( 'OutputPageCheckLastModified',
-						function ( &$modifiedTimes ) {
+						static function ( &$modifiedTimes ) {
 							$modifiedTimes = [ max( $modifiedTimes ) + 1 ];
 						}
 					);
@@ -1196,7 +1196,7 @@ class OutputPageTest extends MediaWikiIntegrationTestCase {
 			$mockContLang
 				->expects( $this->any() )
 				->method( 'convertHtml' )
-				->will( $this->returnCallback( function ( $arg ) {
+				->will( $this->returnCallback( static function ( $arg ) {
 					return $arg;
 				} ) );
 
@@ -1231,7 +1231,7 @@ class OutputPageTest extends MediaWikiIntegrationTestCase {
 
 		$op->expects( $this->any() )
 			->method( 'addCategoryLinksToLBAndGetResult' )
-			->will( $this->returnCallback( function ( array $categories ) use ( $fakeResults ) {
+			->will( $this->returnCallback( static function ( array $categories ) use ( $fakeResults ) {
 				$return = [];
 				foreach ( $categories as $category => $unused ) {
 					if ( isset( $fakeResults[$category] ) ) {
@@ -1291,7 +1291,7 @@ class OutputPageTest extends MediaWikiIntegrationTestCase {
 			'Variant link' => [
 				[ 'Test' => 'Test', 'Estay' => 'Estay' ],
 				[ 'Test' => (object)[ 'page_title' => 'Test' ] ],
-				function ( &$link, &$title ) {
+				static function ( &$link, &$title ) {
 					if ( $link === 'Estay' ) {
 						$link = 'Test';
 						$title = Title::makeTitleSafe( NS_CATEGORY, $link );
diff --git a/tests/phpunit/includes/Permissions/PermissionManagerTest.php b/tests/phpunit/includes/Permissions/PermissionManagerTest.php
index 336e728ad1b..b9bcfa3af6f 100644
--- a/tests/phpunit/includes/Permissions/PermissionManagerTest.php
+++ b/tests/phpunit/includes/Permissions/PermissionManagerTest.php
@@ -858,7 +858,7 @@ class PermissionManagerTest extends MediaWikiLangTestCase {
 		$this->assertNotContains( 'nukeworld', $rights, 'sanity check' );
 
 		// Add a hook manipluating the rights
-		$this->setTemporaryHook( 'UserGetRights', function ( $user, &$rights ) {
+		$this->setTemporaryHook( 'UserGetRights', static function ( $user, &$rights ) {
 			$rights[] = 'nukeworld';
 			$rights = array_diff( $rights, [ 'writetest' ] );
 		} );
diff --git a/tests/phpunit/includes/PrefixSearchTest.php b/tests/phpunit/includes/PrefixSearchTest.php
index 1326b5721aa..3afb22d00c3 100644
--- a/tests/phpunit/includes/PrefixSearchTest.php
+++ b/tests/phpunit/includes/PrefixSearchTest.php
@@ -66,7 +66,7 @@ class PrefixSearchTest extends MediaWikiLangTestCase {
 		} else {
 			$this->setMwGlobals( 'wgHooks', [
 				'PrefixSearchBackend' => [
-					function ( $namespaces, $search, $limit, &$srchres ) use ( $results ) {
+					static function ( $namespaces, $search, $limit, &$srchres ) use ( $results ) {
 						$srchres = $results;
 						return false;
 					}
diff --git a/tests/phpunit/includes/Revision/ContributionsLookupTest.php b/tests/phpunit/includes/Revision/ContributionsLookupTest.php
index 213d425d0d4..ff7ddf8fbdb 100644
--- a/tests/phpunit/includes/Revision/ContributionsLookupTest.php
+++ b/tests/phpunit/includes/Revision/ContributionsLookupTest.php
@@ -75,7 +75,7 @@ class ContributionsLookupTest extends MediaWikiIntegrationTestCase {
 		$user = $this->getTestUser()->getUser();
 
 		$clock = (int)ConvertibleTimestamp::now( TS_UNIX );
-		ConvertibleTimestamp::setFakeTime( function () use ( &$clock ) {
+		ConvertibleTimestamp::setFakeTime( static function () use ( &$clock ) {
 			return ++$clock;
 		} );
 
diff --git a/tests/phpunit/includes/Revision/MutableRevisionSlotsTest.php b/tests/phpunit/includes/Revision/MutableRevisionSlotsTest.php
index 3f7588ae790..c959532047b 100644
--- a/tests/phpunit/includes/Revision/MutableRevisionSlotsTest.php
+++ b/tests/phpunit/includes/Revision/MutableRevisionSlotsTest.php
@@ -147,7 +147,7 @@ class MutableRevisionSlotsTest extends RevisionSlotsTest {
 
 	public function testResetCallback() {
 		$counter = 0;
-		$callback = function () use ( &$counter ) {
+		$callback = static function () use ( &$counter ) {
 			$counter++;
 		};
 
diff --git a/tests/phpunit/includes/Revision/RenderedRevisionTest.php b/tests/phpunit/includes/Revision/RenderedRevisionTest.php
index 41a09027eb5..f053ed29d2b 100644
--- a/tests/phpunit/includes/Revision/RenderedRevisionTest.php
+++ b/tests/phpunit/includes/Revision/RenderedRevisionTest.php
@@ -118,7 +118,7 @@ class RenderedRevisionTest extends MediaWikiIntegrationTestCase {
 			->will( $this->returnValue( true ) );
 		$mock->expects( $this->any() )
 			->method( 'equals' )
-			->willReturnCallback( function ( Title $other ) use ( $mock ) {
+			->willReturnCallback( static function ( Title $other ) use ( $mock ) {
 				return $mock->getPrefixedText() === $other->getPrefixedText();
 			} );
 
diff --git a/tests/phpunit/includes/Revision/RevisionRendererTest.php b/tests/phpunit/includes/Revision/RevisionRendererTest.php
index ed44fda8a60..1df6462ce81 100644
--- a/tests/phpunit/includes/Revision/RevisionRendererTest.php
+++ b/tests/phpunit/includes/Revision/RevisionRendererTest.php
@@ -70,7 +70,7 @@ class RevisionRendererTest extends MediaWikiIntegrationTestCase {
 		$mock->expects( $this->any() )
 			->method( 'equals' )
 			->willReturnCallback(
-				function ( Title $other ) use ( $mock ) {
+				static function ( Title $other ) use ( $mock ) {
 					return $mock->getArticleID() === $other->getArticleID();
 				}
 			);
diff --git a/tests/phpunit/includes/Revision/SlotRecordTest.php b/tests/phpunit/includes/Revision/SlotRecordTest.php
index 96abb7e2ebc..2cf133b7c6d 100644
--- a/tests/phpunit/includes/Revision/SlotRecordTest.php
+++ b/tests/phpunit/includes/Revision/SlotRecordTest.php
@@ -54,17 +54,17 @@ class SlotRecordTest extends \MediaWikiIntegrationTestCase {
 		$row = $this->makeRow( [
 			'content_size' => null, // to be computed
 			'content_sha1' => null, // to be computed
-			'format_name' => function () {
+			'format_name' => static function () {
 				return CONTENT_FORMAT_WIKITEXT;
 			},
 			'slot_revision_id' => '2',
 			'slot_origin' => '2',
-			'slot_content_id' => function () {
+			'slot_content_id' => static function () {
 				return null;
 			},
 		] );
 
-		$content = function () {
+		$content = static function () {
 			return new WikitextContent( 'A' );
 		};
 
diff --git a/tests/phpunit/includes/Revision/SlotRoleRegistryTest.php b/tests/phpunit/includes/Revision/SlotRoleRegistryTest.php
index f6adf21592f..6e53d8f252c 100644
--- a/tests/phpunit/includes/Revision/SlotRoleRegistryTest.php
+++ b/tests/phpunit/includes/Revision/SlotRoleRegistryTest.php
@@ -52,7 +52,7 @@ class SlotRoleRegistryTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testDefineRole() {
 		$registry = $this->newSlotRoleRegistry();
-		$registry->defineRole( 'FOO', function ( $role ) {
+		$registry->defineRole( 'FOO', static function ( $role ) {
 			return new SlotRoleHandler( $role, 'FooModel' );
 		} );
 
@@ -78,12 +78,12 @@ class SlotRoleRegistryTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testDefineRoleFailsForDupe() {
 		$registry = $this->newSlotRoleRegistry();
-		$registry->defineRole( 'foo', function ( $role ) {
+		$registry->defineRole( 'foo', static function ( $role ) {
 			return new SlotRoleHandler( $role, 'FooModel' );
 		} );
 
 		$this->expectException( LogicException::class );
-		$registry->defineRole( 'FOO', function ( $role ) {
+		$registry->defineRole( 'FOO', static function ( $role ) {
 			return new SlotRoleHandler( $role, 'FooModel' );
 		} );
 	}
@@ -143,7 +143,7 @@ class SlotRoleRegistryTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testGetRoleHandlerWithBadInstantiator() {
 		$registry = $this->newSlotRoleRegistry();
-		$registry->defineRole( 'foo', function ( $role ) {
+		$registry->defineRole( 'foo', static function ( $role ) {
 			return 'Not a SlotRoleHandler instance';
 		} );
 
diff --git a/tests/phpunit/includes/RevisionDbTest.php b/tests/phpunit/includes/RevisionDbTest.php
index d872d5b601a..97b574c5193 100644
--- a/tests/phpunit/includes/RevisionDbTest.php
+++ b/tests/phpunit/includes/RevisionDbTest.php
@@ -428,41 +428,41 @@ class RevisionDbTest extends MediaWikiIntegrationTestCase {
 
 	public function provideNewFromArchiveRow() {
 		yield [
-			function ( $f ) {
+			static function ( $f ) {
 				return $f;
 			},
 		];
 		yield [
-			function ( $f ) {
+			static function ( $f ) {
 				return $f + [ 'ar_namespace', 'ar_title' ];
 			},
 		];
 		yield [
-			function ( $f ) {
+			static function ( $f ) {
 				unset( $f['ar_text_id'] );
 				return $f;
 			},
 		];
 		yield [
-			function ( $f ) {
+			static function ( $f ) {
 				unset( $f['ar_page_id'] );
 				return $f;
 			},
 		];
 		yield [
-			function ( $f ) {
+			static function ( $f ) {
 				unset( $f['ar_parent_id'] );
 				return $f;
 			},
 		];
 		yield [
-			function ( $f ) {
+			static function ( $f ) {
 				unset( $f['ar_rev_id'] );
 				return $f;
 			},
 		];
 		yield [
-			function ( $f ) {
+			static function ( $f ) {
 				unset( $f['ar_sha1'] );
 				return $f;
 			},
diff --git a/tests/phpunit/includes/RevisionTest.php b/tests/phpunit/includes/RevisionTest.php
index e9341fe3f0b..9555f83d4a1 100644
--- a/tests/phpunit/includes/RevisionTest.php
+++ b/tests/phpunit/includes/RevisionTest.php
@@ -213,7 +213,7 @@ class RevisionTest extends MediaWikiIntegrationTestCase {
 				'rev_comment_data' => null,
 				'rev_comment_cid' => null,
 			],
-			function ( RevisionTest $testCase, Revision $rev ) {
+			static function ( RevisionTest $testCase, Revision $rev ) {
 				$testCase->hideDeprecated( 'Revision::getSha1' );
 				$testCase->hideDeprecated( 'Revision::getUserText' );
 				$testCase->hideDeprecated( 'Revision::isMinor' );
@@ -250,7 +250,7 @@ class RevisionTest extends MediaWikiIntegrationTestCase {
 				'rev_comment_data' => null,
 				'rev_comment_cid' => null,
 			],
-			function ( RevisionTest $testCase, Revision $rev ) {
+			static function ( RevisionTest $testCase, Revision $rev ) {
 				$testCase->hideDeprecated( 'Revision::getUserText' );
 				$testCase->hideDeprecated( 'Revision::isMinor' );
 				$testCase->hideDeprecated( 'Revision::getParentId' );
diff --git a/tests/phpunit/includes/StatusTest.php b/tests/phpunit/includes/StatusTest.php
index eced84a6275..ef9470aaf06 100644
--- a/tests/phpunit/includes/StatusTest.php
+++ b/tests/phpunit/includes/StatusTest.php
@@ -741,7 +741,7 @@ class StatusTest extends MediaWikiLangTestCase {
 			->getMockForAbstractClass();
 		$messageLocalizer->expects( $this->atLeastOnce() )
 			->method( 'msg' )
-			->willReturnCallback( function ( $key ) {
+			->willReturnCallback( static function ( $key ) {
 				return new RawMessage( $key );
 			} );
 		/** @var MessageLocalizer $messageLocalizer */
diff --git a/tests/phpunit/includes/Storage/DerivedPageDataUpdaterTest.php b/tests/phpunit/includes/Storage/DerivedPageDataUpdaterTest.php
index e93f1363d35..641f23cec44 100644
--- a/tests/phpunit/includes/Storage/DerivedPageDataUpdaterTest.php
+++ b/tests/phpunit/includes/Storage/DerivedPageDataUpdaterTest.php
@@ -515,7 +515,7 @@ class DerivedPageDataUpdaterTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testGetPreparedEditAfterPrepareUpdate() {
 		$clock = MWTimestamp::convert( TS_UNIX, '20100101000000' );
-		MWTimestamp::setFakeTime( function () use ( &$clock ) {
+		MWTimestamp::setFakeTime( static function () use ( &$clock ) {
 			return $clock++;
 		} );
 
@@ -592,7 +592,7 @@ class DerivedPageDataUpdaterTest extends MediaWikiIntegrationTestCase {
 
 		$this->mergeMwGlobalArrayValue(
 			'wgContentHandlers', [
-				$name => function () use ( $handler ){
+				$name => static function () use ( $handler ){
 					return $handler;
 				}
 			]
diff --git a/tests/phpunit/includes/Storage/NameTableStoreTest.php b/tests/phpunit/includes/Storage/NameTableStoreTest.php
index ede98e3361a..bb9304cb034 100644
--- a/tests/phpunit/includes/Storage/NameTableStoreTest.php
+++ b/tests/phpunit/includes/Storage/NameTableStoreTest.php
@@ -56,7 +56,7 @@ class NameTableStoreTest extends MediaWikiIntegrationTestCase {
 			->getMock();
 		$mock->expects( $this->any() )
 			->method( 'getConnectionRef' )
-			->willReturnCallback( function ( $i ) use ( $mock, $db ) {
+			->willReturnCallback( static function ( $i ) use ( $mock, $db ) {
 				return new MaintainableDBConnRef( $mock, $db, $i );
 			} );
 		return $mock;
@@ -190,7 +190,7 @@ class NameTableStoreTest extends MediaWikiIntegrationTestCase {
 		yield [
 			'X',
 			'X',
-			function ( $name ) {
+			static function ( $name ) {
 				return $name;
 			}
 		];
@@ -350,7 +350,7 @@ class NameTableStoreTest extends MediaWikiIntegrationTestCase {
 			1,
 			1,
 			null,
-			function ( $insertFields ) {
+			static function ( $insertFields ) {
 				$insertFields['role_id'] = 7251;
 				return $insertFields;
 			}
@@ -388,7 +388,7 @@ class NameTableStoreTest extends MediaWikiIntegrationTestCase {
 
 		$db = $this->getProxyDb( 2 );
 		$db->method( 'insert' )
-			->willReturnCallback( function () use ( &$insertCalls, $db ) {
+			->willReturnCallback( static function () use ( &$insertCalls, $db ) {
 				$insertCalls++;
 				switch ( $insertCalls ) {
 					case 1:
@@ -447,7 +447,7 @@ class NameTableStoreTest extends MediaWikiIntegrationTestCase {
 
 		$quuxId = null;
 		$this->db->onTransactionResolution(
-			function () use ( $store1, &$quuxId ) {
+			static function () use ( $store1, &$quuxId ) {
 				$quuxId = $store1->acquireId( 'quux' );
 			}
 		);
diff --git a/tests/phpunit/includes/Storage/PageUpdaterTest.php b/tests/phpunit/includes/Storage/PageUpdaterTest.php
index 17bb2de5abc..ae7e466a8db 100644
--- a/tests/phpunit/includes/Storage/PageUpdaterTest.php
+++ b/tests/phpunit/includes/Storage/PageUpdaterTest.php
@@ -460,7 +460,7 @@ class PageUpdaterTest extends MediaWikiIntegrationTestCase {
 
 		$expectedError = 'aborted-by-test-hook';
 		$this->setTemporaryHook( 'MultiContentSave',
-			function ( RenderedRevision $renderedRevision, User $user,
+			static function ( RenderedRevision $renderedRevision, User $user,
 				$summary, $flags, Status $hookStatus
 			) use ( $expectedError ) {
 				$hookStatus->fatal( $expectedError );
@@ -788,35 +788,35 @@ class PageUpdaterTest extends MediaWikiIntegrationTestCase {
 	public function provideMagicWords() {
 		yield 'PAGEID' => [
 			'Test {{PAGEID}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return $rev->getPageId();
 			}
 		];
 
 		yield 'REVISIONID' => [
 			'Test {{REVISIONID}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return $rev->getId();
 			}
 		];
 
 		yield 'REVISIONUSER' => [
 			'Test {{REVISIONUSER}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return $rev->getUser()->getName();
 			}
 		];
 
 		yield 'REVISIONTIMESTAMP' => [
 			'Test {{REVISIONTIMESTAMP}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return $rev->getTimestamp();
 			}
 		];
 
 		yield 'subst:REVISIONUSER' => [
 			'Test {{subst:REVISIONUSER}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return $rev->getUser()->getName();
 			},
 			'subst'
@@ -824,7 +824,7 @@ class PageUpdaterTest extends MediaWikiIntegrationTestCase {
 
 		yield 'subst:PAGENAME' => [
 			'Test {{subst:PAGENAME}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return 'PageUpdaterTest::testMagicWords';
 			},
 			'subst'
diff --git a/tests/phpunit/includes/TitleMethodsTest.php b/tests/phpunit/includes/TitleMethodsTest.php
index ff63e77af2a..74e6e5ef729 100644
--- a/tests/phpunit/includes/TitleMethodsTest.php
+++ b/tests/phpunit/includes/TitleMethodsTest.php
@@ -407,12 +407,12 @@ class TitleMethodsTest extends MediaWikiLangTestCase {
 		];
 
 		$interwikiLookup->method( 'fetch' )
-			->willReturnCallback( function ( $interwiki ) use ( $interwikis ) {
+			->willReturnCallback( static function ( $interwiki ) use ( $interwikis ) {
 				return $interwikis[$interwiki] ?? false;
 			} );
 
 		$interwikiLookup->method( 'isValidInterwiki' )
-			->willReturnCallback( function ( $interwiki ) use ( $interwikis ) {
+			->willReturnCallback( static function ( $interwiki ) use ( $interwikis ) {
 				return isset( $interwikis[$interwiki] );
 			} );
 
diff --git a/tests/phpunit/includes/TitleTest.php b/tests/phpunit/includes/TitleTest.php
index a73482d7df2..d4620cc7cfb 100644
--- a/tests/phpunit/includes/TitleTest.php
+++ b/tests/phpunit/includes/TitleTest.php
@@ -486,7 +486,7 @@ class TitleTest extends MediaWikiIntegrationTestCase {
 		$interwikiLookup->expects( $this->any() )
 			->method( 'isValidInterwiki' )
 			->willReturnCallback(
-				function ( $prefix ) {
+				static function ( $prefix ) {
 					return $prefix == 'wiki';
 				}
 			);
@@ -1039,7 +1039,7 @@ class TitleTest extends MediaWikiIntegrationTestCase {
 			'Interwiki' => [ Title::makeTitle( NS_MAIN, 'Test', '', 'otherwiki' ), false ],
 			'Special page' => [ 'Special:FooBar', false ],
 			'Aborted by hook' => [ 'Hooked in place', false,
-				function ( Title $title, &$result ) {
+				static function ( Title $title, &$result ) {
 					$result = false;
 				}
 			],
diff --git a/tests/phpunit/includes/WebRequestTest.php b/tests/phpunit/includes/WebRequestTest.php
index 7242e58dbea..42f2e701b14 100644
--- a/tests/phpunit/includes/WebRequestTest.php
+++ b/tests/phpunit/includes/WebRequestTest.php
@@ -399,7 +399,7 @@ class WebRequestTest extends MediaWikiIntegrationTestCase {
 			'wgUsePrivateIPs' => $private,
 			'wgHooks' => [
 				'IsTrustedProxy' => [
-					function ( &$ip, &$trusted ) use ( $xffList ) {
+					static function ( &$ip, &$trusted ) use ( $xffList ) {
 						$trusted = $trusted || in_array( $ip, $xffList );
 						return true;
 					}
diff --git a/tests/phpunit/includes/actions/WatchActionTest.php b/tests/phpunit/includes/actions/WatchActionTest.php
index bc46e13206c..b39e60d32ee 100644
--- a/tests/phpunit/includes/actions/WatchActionTest.php
+++ b/tests/phpunit/includes/actions/WatchActionTest.php
@@ -112,7 +112,7 @@ class WatchActionTest extends MediaWikiIntegrationTestCase {
 			$testContext
 		);
 
-		Hooks::register( 'WatchArticle', function () {
+		Hooks::register( 'WatchArticle', static function () {
 			return false;
 		} );
 
@@ -173,7 +173,7 @@ class WatchActionTest extends MediaWikiIntegrationTestCase {
 			->getMock();
 		$testOutput = new OutputPage( $testContext );
 		$testContext->setOutput( $testOutput );
-		$testContext->method( 'msg' )->willReturnCallback( function ( $msgKey ) {
+		$testContext->method( 'msg' )->willReturnCallback( static function ( $msgKey ) {
 			return new RawMessage( $msgKey );
 		} );
 		$watchAction = new WatchAction(
@@ -198,7 +198,7 @@ class WatchActionTest extends MediaWikiIntegrationTestCase {
 			->getMock();
 		$testOutput = new OutputPage( $testContext );
 		$testContext->method( 'getOutput' )->willReturn( $testOutput );
-		$testContext->method( 'msg' )->willReturnCallback( function ( $msgKey ) {
+		$testContext->method( 'msg' )->willReturnCallback( static function ( $msgKey ) {
 			return new RawMessage( $msgKey );
 		} );
 		$talkPageTitle = Title::newFromText( 'Talk:UTTest' );
@@ -371,7 +371,7 @@ class WatchActionTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testDoUnWatchUserHookAborted() {
 		$permittedUser = $this->getUser( false, null, [ 'editmywatchlist' ] );
-		Hooks::register( 'UnwatchArticle', function () {
+		Hooks::register( 'UnwatchArticle', static function () {
 			return false;
 		} );
 
diff --git a/tests/phpunit/includes/api/ApiCSPReportTest.php b/tests/phpunit/includes/api/ApiCSPReportTest.php
index 14a84c26a21..8bfde4ccde3 100644
--- a/tests/phpunit/includes/api/ApiCSPReportTest.php
+++ b/tests/phpunit/includes/api/ApiCSPReportTest.php
@@ -84,7 +84,7 @@ class ApiCSPReportTest extends MediaWikiIntegrationTestCase {
 		$log = [];
 		$logger = $this->createMock( Psr\Log\AbstractLogger::class );
 		$logger->method( 'warning' )->will( $this->returnCallback(
-			function ( $msg, $ctx ) use ( &$log ) {
+			static function ( $msg, $ctx ) use ( &$log ) {
 				unset( $ctx['csp-report'] );
 				$log[] = [ $msg, $ctx ];
 			}
@@ -107,7 +107,7 @@ class ApiCSPReportTest extends MediaWikiIntegrationTestCase {
 			->setMethods( [ 'getParameter', 'getRequest', 'getResult' ] )
 			->getMock();
 		$api->method( 'getParameter' )->will( $this->returnCallback(
-			function ( $key ) use ( $req ) {
+			static function ( $key ) use ( $req ) {
 				return $req->getRawVal( $key );
 			}
 		) );
diff --git a/tests/phpunit/includes/api/ApiChangeContentModelTest.php b/tests/phpunit/includes/api/ApiChangeContentModelTest.php
index 79f72a189c1..12b206c99e2 100644
--- a/tests/phpunit/includes/api/ApiChangeContentModelTest.php
+++ b/tests/phpunit/includes/api/ApiChangeContentModelTest.php
@@ -144,7 +144,7 @@ class ApiChangeContentModelTest extends ApiTestCase {
 		);
 
 		$this->setTemporaryHook( 'EditFilterMergedContent',
-			function ( $unused1, $unused2, Status $status ) use ( $customMessage ) {
+			static function ( $unused1, $unused2, Status $status ) use ( $customMessage ) {
 				if ( $customMessage !== false ) {
 					$status->fatal( $customMessage );
 				}
@@ -187,7 +187,7 @@ class ApiChangeContentModelTest extends ApiTestCase {
 		);
 
 		$this->setTemporaryHook( 'ContentModelCanBeUsedOn',
-			function ( $unused1, $unused2, &$ok ) {
+			static function ( $unused1, $unused2, &$ok ) {
 				$ok = false;
 				return false;
 			}
diff --git a/tests/phpunit/includes/api/ApiDeleteTest.php b/tests/phpunit/includes/api/ApiDeleteTest.php
index 20aa45078ab..af34dfecef5 100644
--- a/tests/phpunit/includes/api/ApiDeleteTest.php
+++ b/tests/phpunit/includes/api/ApiDeleteTest.php
@@ -177,7 +177,7 @@ class ApiDeleteTest extends ApiTestCase {
 		$this->editPage( $name, 'Some text' );
 
 		$this->setTemporaryHook( 'ArticleDelete',
-			function () {
+			static function () {
 				return false;
 			}
 		);
diff --git a/tests/phpunit/includes/api/ApiEditPageTest.php b/tests/phpunit/includes/api/ApiEditPageTest.php
index 5e3df7e03d8..7b40f044b3c 100644
--- a/tests/phpunit/includes/api/ApiEditPageTest.php
+++ b/tests/phpunit/includes/api/ApiEditPageTest.php
@@ -1040,7 +1040,7 @@ class ApiEditPageTest extends ApiTestCase {
 		$this->expectExceptionMessage( "Can't append to pages using content model testing-nontext." );
 
 		$this->setTemporaryHook( 'ContentHandlerDefaultModelFor',
-			function ( Title $title, &$model ) use ( $name ) {
+			static function ( Title $title, &$model ) use ( $name ) {
 				if ( $title->getPrefixedText() === $name ) {
 					$model = 'testing-nontext';
 				}
@@ -1076,7 +1076,7 @@ class ApiEditPageTest extends ApiTestCase {
 		$this->expectExceptionMessage( 'Content serialization failed: Could not unserialize content' );
 
 		$this->setTemporaryHook( 'ContentHandlerDefaultModelFor',
-			function ( Title $title, &$model ) use ( $name ) {
+			static function ( Title $title, &$model ) use ( $name ) {
 				if ( $title->getPrefixedText() === $name ) {
 					$model = 'testing-serialize-error';
 				}
@@ -1436,7 +1436,7 @@ class ApiEditPageTest extends ApiTestCase {
 		$name = 'Help:' . ucfirst( __FUNCTION__ );
 
 		$this->setTemporaryHook( 'EditFilterMergedContent',
-			function ( $unused1, $unused2, Status $status ) {
+			static function ( $unused1, $unused2, Status $status ) {
 				$status->apiHookResult = [ 'msg' => 'A message for you!' ];
 				return false;
 			} );
@@ -1461,7 +1461,7 @@ class ApiEditPageTest extends ApiTestCase {
 		);
 
 		$this->setTemporaryHook( 'EditFilterMergedContent',
-			function () {
+			static function () {
 				return false;
 			}
 		);
diff --git a/tests/phpunit/includes/api/ApiLoginTest.php b/tests/phpunit/includes/api/ApiLoginTest.php
index d9e361ae7ea..214f8ad2ff0 100644
--- a/tests/phpunit/includes/api/ApiLoginTest.php
+++ b/tests/phpunit/includes/api/ApiLoginTest.php
@@ -235,7 +235,7 @@ class ApiLoginTest extends ApiTestCase {
 
 		$this->mergeMwGlobalArrayValue( 'wgAuthManagerConfig', [
 			'secondaryauth' => [ [
-				'factory' => function () use ( $mockProvider ) {
+				'factory' => static function () use ( $mockProvider ) {
 					return $mockProvider;
 				},
 			] ],
@@ -346,7 +346,7 @@ class ApiLoginTest extends ApiTestCase {
 	}
 
 	public function testBotPasswordLocked() {
-		$this->setTemporaryHook( 'UserIsLocked', function ( User $unused, &$isLocked ) {
+		$this->setTemporaryHook( 'UserIsLocked', static function ( User $unused, &$isLocked ) {
 			$isLocked = true;
 			return true;
 		} );
@@ -361,7 +361,7 @@ class ApiLoginTest extends ApiTestCase {
 
 	public function testNoSameOriginSecurity() {
 		$this->setTemporaryHook( 'RequestHasSameOriginSecurity',
-			function () {
+			static function () {
 				return false;
 			}
 		);
diff --git a/tests/phpunit/includes/api/ApiMainTest.php b/tests/phpunit/includes/api/ApiMainTest.php
index 7bd55e91d44..4b65b17b768 100644
--- a/tests/phpunit/includes/api/ApiMainTest.php
+++ b/tests/phpunit/includes/api/ApiMainTest.php
@@ -249,7 +249,7 @@ class ApiMainTest extends ApiTestCase {
 		$api = new ApiMain( new FauxRequest( [ 'action' => 'testmodule' ] ) );
 		$api->getModuleManager()->addModule( 'testmodule', 'action', [
 			'class' => get_class( $mock ),
-			'factory' => function () use ( $mock ) {
+			'factory' => static function () use ( $mock ) {
 				return $mock;
 			}
 		] );
@@ -268,7 +268,7 @@ class ApiMainTest extends ApiTestCase {
 		$api = new ApiMain( new FauxRequest( [ 'action' => 'testmodule' ] ) );
 		$api->getModuleManager()->addModule( 'testmodule', 'action', [
 			'class' => get_class( $mock ),
-			'factory' => function () use ( $mock ) {
+			'factory' => static function () use ( $mock ) {
 				return $mock;
 			}
 		] );
@@ -318,7 +318,7 @@ class ApiMainTest extends ApiTestCase {
 		$api = new ApiMain( $req );
 		$api->getModuleManager()->addModule( 'testmodule', 'action', [
 			'class' => get_class( $mock ),
-			'factory' => function () use ( $mock ) {
+			'factory' => static function () use ( $mock ) {
 				return $mock;
 			}
 		] );
@@ -530,7 +530,7 @@ class ApiMainTest extends ApiTestCase {
 			->getMockForAbstractClass();
 		$module->expects( $this->any() )
 			->method( 'getConditionalRequestData' )
-			->will( $this->returnCallback( function ( $condition ) use ( $conditions ) {
+			->will( $this->returnCallback( static function ( $condition ) use ( $conditions ) {
 				return $conditions[$condition] ?? null;
 			} ) );
 
@@ -661,7 +661,7 @@ class ApiMainTest extends ApiTestCase {
 			->getMockForAbstractClass();
 		$module->expects( $this->any() )
 			->method( 'getConditionalRequestData' )
-			->will( $this->returnCallback( function ( $condition ) use ( $conditions ) {
+			->will( $this->returnCallback( static function ( $condition ) use ( $conditions ) {
 				return $conditions[$condition] ?? null;
 			} ) );
 		$priv->mModule = $module;
@@ -767,7 +767,7 @@ class ApiMainTest extends ApiTestCase {
 		$this->expectException( ApiUsageException::class );
 		$this->expectExceptionMessage( 'Main Page' );
 
-		$this->setTemporaryHook( 'ApiCheckCanExecute', function ( $unused1, $unused2, &$message ) {
+		$this->setTemporaryHook( 'ApiCheckCanExecute', static function ( $unused1, $unused2, &$message ) {
 			$message = 'mainpage';
 			return false;
 		} );
@@ -824,7 +824,7 @@ class ApiMainTest extends ApiTestCase {
 
 		// Hook
 		$this->mergeMwGlobalArrayValue( 'wgHooks', [
-			'RequestHasSameOriginSecurity' => [ function () {
+			'RequestHasSameOriginSecurity' => [ static function () {
 				return false;
 			} ]
 		] );
diff --git a/tests/phpunit/includes/api/ApiModuleManagerTest.php b/tests/phpunit/includes/api/ApiModuleManagerTest.php
index e060e63e2a1..3f6e247487a 100644
--- a/tests/phpunit/includes/api/ApiModuleManagerTest.php
+++ b/tests/phpunit/includes/api/ApiModuleManagerTest.php
@@ -63,7 +63,7 @@ class ApiModuleManagerTest extends MediaWikiIntegrationTestCase {
 				'action',
 				[
 					'class' => ApiLogout::class,
-					'factory' => function ( ApiMain $main, $action, ObjectFactory $objectFactory ) {
+					'factory' => static function ( ApiMain $main, $action, ObjectFactory $objectFactory ) {
 						return new ApiLogout( $main, $action );
 					},
 					'services' => [
@@ -115,7 +115,7 @@ class ApiModuleManagerTest extends MediaWikiIntegrationTestCase {
 					],
 					'logout' => [
 						'class' => ApiLogout::class,
-						'factory' => function ( ApiMain $main, $action ) {
+						'factory' => static function ( ApiMain $main, $action ) {
 							return new ApiLogout( $main, $action );
 						},
 					],
@@ -150,7 +150,7 @@ class ApiModuleManagerTest extends MediaWikiIntegrationTestCase {
 			],
 			'logout' => [
 				'class' => ApiLogout::class,
-				'factory' => function ( ApiMain $main, $action ) {
+				'factory' => static function ( ApiMain $main, $action ) {
 					return new ApiLogout( $main, $action );
 				},
 			],
@@ -372,7 +372,7 @@ class ApiModuleManagerTest extends MediaWikiIntegrationTestCase {
 			'logout',
 			'action',
 			[
-				'factory' => function ( ApiMain $main, $action ) {
+				'factory' => static function ( ApiMain $main, $action ) {
 					return new ApiLogout( $main, $action );
 				},
 			]
diff --git a/tests/phpunit/includes/api/ApiPageSetTest.php b/tests/phpunit/includes/api/ApiPageSetTest.php
index dbfc4eab779..66436c60abe 100644
--- a/tests/phpunit/includes/api/ApiPageSetTest.php
+++ b/tests/phpunit/includes/api/ApiPageSetTest.php
@@ -18,7 +18,7 @@ class ApiPageSetTest extends ApiTestCase {
 			],
 
 			'A simple merge policy adds the redirect data in' => [
-				function ( $current, $new ) {
+				static function ( $current, $new ) {
 					if ( !isset( $current['index'] ) || $new['index'] < $current['index'] ) {
 						$current['index'] = $new['index'];
 					}
@@ -88,7 +88,7 @@ class ApiPageSetTest extends ApiTestCase {
 		list( $target, $pageSet ) = $this->createPageSetWithRedirect(
 			'#REDIRECT [[UTPageRedirectOne]]'
 		);
-		$pageSet->setRedirectMergePolicy( function ( $cur, $new ) {
+		$pageSet->setRedirectMergePolicy( static function ( $cur, $new ) {
 			throw new \RuntimeException( 'unreachable, no merge when target is redirect loop' );
 		} );
 		// This could infinite loop in a bugged impl, but php doesn't offer
diff --git a/tests/phpunit/includes/api/ApiParseTest.php b/tests/phpunit/includes/api/ApiParseTest.php
index 9892a1879b0..93b92a336a2 100644
--- a/tests/phpunit/includes/api/ApiParseTest.php
+++ b/tests/phpunit/includes/api/ApiParseTest.php
@@ -614,7 +614,7 @@ class ApiParseTest extends ApiTestCase {
 	public function testEffectiveLangLinks() {
 		$hookRan = false;
 		$this->setTemporaryHook( 'LanguageLinks',
-			function () use ( &$hookRan ) {
+			static function () use ( &$hookRan ) {
 				$hookRan = true;
 			}
 		);
@@ -701,7 +701,7 @@ class ApiParseTest extends ApiTestCase {
 
 	public function testModules() {
 		$this->setTemporaryHook( 'ParserAfterParse',
-			function ( $parser ) {
+			static function ( $parser ) {
 				$output = $parser->getOutput();
 				$output->addModules( [ 'foo', 'bar' ] );
 				$output->addModuleStyles( [ 'aaa', 'zzz' ] );
diff --git a/tests/phpunit/includes/api/Validator/ApiParamValidatorCallbacksTest.php b/tests/phpunit/includes/api/Validator/ApiParamValidatorCallbacksTest.php
index 519ae1765d8..2c24e9d759f 100644
--- a/tests/phpunit/includes/api/Validator/ApiParamValidatorCallbacksTest.php
+++ b/tests/phpunit/includes/api/Validator/ApiParamValidatorCallbacksTest.php
@@ -174,13 +174,13 @@ class ApiParamValidatorCallbacksTest extends ApiUploadTestCase {
 			->setMethods( [ 'addWarning' ] )
 			->getMockForAbstractClass();
 		$module->method( 'addWarning' )->willReturnCallback(
-			function ( $msg, $code, $data ) use ( &$warnings ) {
+			static function ( $msg, $code, $data ) use ( &$warnings ) {
 				$warnings[] = [ $msg, $code, $data ];
 			}
 		);
 		$query->getModuleManager()->addModule( 'test', 'meta', [
 			'class' => get_class( $module ),
-			'factory' => function () use ( $module ) {
+			'factory' => static function () use ( $module ) {
 				return $module;
 			}
 		] );
diff --git a/tests/phpunit/includes/api/Validator/SubmoduleDefTest.php b/tests/phpunit/includes/api/Validator/SubmoduleDefTest.php
index 76b51920a19..a2579952100 100644
--- a/tests/phpunit/includes/api/Validator/SubmoduleDefTest.php
+++ b/tests/phpunit/includes/api/Validator/SubmoduleDefTest.php
@@ -30,7 +30,7 @@ class SubmoduleDefTest extends TypeDefTestCase {
 
 		$w->mMainModule->getModuleManager()->addModule( 'testmod', 'action', [
 			'class' => MockApi::class,
-			'factory' => function () use ( $api ) {
+			'factory' => static function () use ( $api ) {
 				return $api;
 			},
 		] );
@@ -55,25 +55,25 @@ class SubmoduleDefTest extends TypeDefTestCase {
 		$manager->addModule( 'mod2', 'test', MockApi::class );
 		$manager->addModule( 'dep', 'test', [
 			'class' => MockApi::class,
-			'factory' => function () use ( $dep ) {
+			'factory' => static function () use ( $dep ) {
 				return $dep;
 			},
 		] );
 		$manager->addModule( 'depint', 'test', [
 			'class' => MockApi::class,
-			'factory' => function () use ( $depint ) {
+			'factory' => static function () use ( $depint ) {
 				return $depint;
 			},
 		] );
 		$manager->addModule( 'int', 'test', [
 			'class' => MockApi::class,
-			'factory' => function () use ( $int ) {
+			'factory' => static function () use ( $int ) {
 				return $int;
 			},
 		] );
 		$manager->addModule( 'recurse', 'test', [
 			'class' => MockApi::class,
-			'factory' => function () use ( $api ) {
+			'factory' => static function () use ( $api ) {
 				return $api;
 			},
 		] );
diff --git a/tests/phpunit/includes/api/format/ApiFormatBaseTest.php b/tests/phpunit/includes/api/format/ApiFormatBaseTest.php
index bf22eeede97..326c80b10d2 100644
--- a/tests/phpunit/includes/api/format/ApiFormatBaseTest.php
+++ b/tests/phpunit/includes/api/format/ApiFormatBaseTest.php
@@ -47,7 +47,7 @@ class ApiFormatBaseTest extends ApiFormatTestBase {
 			'factory' => function ( ApiMain $main, $format ) use ( $options ) {
 				$mock = $this->getMockFormatter( $main, $format );
 				$mock->expects( $this->once() )->method( 'execute' )
-					->willReturnCallback( function () use ( $mock ) {
+					->willReturnCallback( static function () use ( $mock ) {
 						$mock->printText( "Format {$mock->getFormat()}: " );
 						$mock->printText( "<b>ok</b>" );
 					} );
@@ -216,7 +216,7 @@ class ApiFormatBaseTest extends ApiFormatTestBase {
 		] );
 
 		$printer = $this->getMockFormatter( null, 'mock' );
-		$printer->method( 'execute' )->willReturnCallback( function () use ( $printer ) {
+		$printer->method( 'execute' )->willReturnCallback( static function () use ( $printer ) {
 			$printer->printText( 'Foo' );
 		} );
 		$this->assertFalse( $printer->isDisabled() );
@@ -242,7 +242,7 @@ class ApiFormatBaseTest extends ApiFormatTestBase {
 		] );
 
 		$printer = $this->getMockFormatter( null, 'mock', [ 'getMimeType' ] );
-		$printer->method( 'execute' )->willReturnCallback( function () use ( $printer ) {
+		$printer->method( 'execute' )->willReturnCallback( static function () use ( $printer ) {
 			$printer->printText( 'Foo' );
 		} );
 		$printer->method( 'getMimeType' )->willReturn( null );
@@ -259,7 +259,7 @@ class ApiFormatBaseTest extends ApiFormatTestBase {
 		$this->assertNull( $response->getHeader( 'Content-Disposition' ) );
 
 		$printer = $this->getMockFormatter( null, 'mockfm', [ 'getMimeType' ] );
-		$printer->method( 'execute' )->willReturnCallback( function () use ( $printer ) {
+		$printer->method( 'execute' )->willReturnCallback( static function () use ( $printer ) {
 			$printer->printText( 'Foo' );
 		} );
 		$printer->method( 'getMimeType' )->willReturn( null );
@@ -375,14 +375,14 @@ class ApiFormatBaseTest extends ApiFormatTestBase {
 		$mm = $printer->getMain()->getModuleManager();
 		$mm->addModule( 'mockfm', 'format', [
 			'class' => ApiFormatBase::class,
-			'factory' => function () {
+			'factory' => static function () {
 				return $mock;
 			}
 		] );
 		if ( $registerNonHtml ) {
 			$mm->addModule( 'mock', 'format', [
 				'class' => ApiFormatBase::class,
-				'factory' => function () {
+				'factory' => static function () {
 					return $mock;
 				}
 			] );
diff --git a/tests/phpunit/includes/api/format/ApiFormatRawTest.php b/tests/phpunit/includes/api/format/ApiFormatRawTest.php
index f64af6d3a8e..a5d9d3f6f2c 100644
--- a/tests/phpunit/includes/api/format/ApiFormatRawTest.php
+++ b/tests/phpunit/includes/api/format/ApiFormatRawTest.php
@@ -15,7 +15,7 @@ class ApiFormatRawTest extends ApiFormatTestBase {
 	public static function provideGeneralEncoding() {
 		$options = [
 			'class' => ApiFormatRaw::class,
-			'factory' => function ( ApiMain $main ) {
+			'factory' => static function ( ApiMain $main ) {
 				return new ApiFormatRaw( $main, new ApiFormatJson( $main, 'json' ) );
 			}
 		];
@@ -106,7 +106,7 @@ class ApiFormatRawTest extends ApiFormatTestBase {
 			[],
 			[
 				'class' => ApiFormatRaw::class,
-				'factory' => function ( ApiMain $main ) use ( &$apiMain ) {
+				'factory' => static function ( ApiMain $main ) use ( &$apiMain ) {
 					$apiMain = $main;
 					$printer = new ApiFormatRaw( $main, new ApiFormatJson( $main, 'json' ) );
 					$printer->setFailWithHTTPError( true );
diff --git a/tests/phpunit/includes/api/query/ApiQueryBlockInfoTraitTest.php b/tests/phpunit/includes/api/query/ApiQueryBlockInfoTraitTest.php
index dc4d2adcad8..4b374487d8f 100644
--- a/tests/phpunit/includes/api/query/ApiQueryBlockInfoTraitTest.php
+++ b/tests/phpunit/includes/api/query/ApiQueryBlockInfoTraitTest.php
@@ -30,16 +30,16 @@ class ApiQueryBlockInfoTraitTest extends MediaWikiIntegrationTestCase {
 			->willReturn( MediaWikiServices::getInstance()->getPermissionManager() );
 		$mock->method( 'getUser' )
 			->willReturn( $this->getMutableTestUser()->getUser() );
-		$mock->method( 'addTables' )->willReturnCallback( function ( $v ) use ( &$data ) {
+		$mock->method( 'addTables' )->willReturnCallback( static function ( $v ) use ( &$data ) {
 			$data['tables'] = array_merge( $data['tables'] ?? [], (array)$v );
 		} );
-		$mock->method( 'addFields' )->willReturnCallback( function ( $v ) use ( &$data ) {
+		$mock->method( 'addFields' )->willReturnCallback( static function ( $v ) use ( &$data ) {
 			$data['fields'] = array_merge( $data['fields'] ?? [], (array)$v );
 		} );
-		$mock->method( 'addWhere' )->willReturnCallback( function ( $v ) use ( &$data ) {
+		$mock->method( 'addWhere' )->willReturnCallback( static function ( $v ) use ( &$data ) {
 			$data['where'] = array_merge( $data['where'] ?? [], (array)$v );
 		} );
-		$mock->method( 'addJoinConds' )->willReturnCallback( function ( $v ) use ( &$data ) {
+		$mock->method( 'addJoinConds' )->willReturnCallback( static function ( $v ) use ( &$data ) {
 			$data['joins'] = array_merge( $data['joins'] ?? [], (array)$v );
 		} );
 
diff --git a/tests/phpunit/includes/api/query/ApiQueryLanguageinfoTest.php b/tests/phpunit/includes/api/query/ApiQueryLanguageinfoTest.php
index 23e60349951..cbf6d67495b 100644
--- a/tests/phpunit/includes/api/query/ApiQueryLanguageinfoTest.php
+++ b/tests/phpunit/includes/api/query/ApiQueryLanguageinfoTest.php
@@ -15,7 +15,7 @@ class ApiQueryLanguageinfoTest extends ApiTestCase {
 		// register custom language names so this test is independent of CLDR
 		$this->setTemporaryHook(
 			'LanguageGetTranslatedLanguageNames',
-			function ( array &$names, $code ) {
+			static function ( array &$names, $code ) {
 				switch ( $code ) {
 					case 'en':
 						$names['sh'] = 'Serbo-Croatian';
@@ -41,13 +41,13 @@ class ApiQueryLanguageinfoTest extends ApiTestCase {
 			// so we can call the constructor with the custom $microtimeFunction
 			$this->setTemporaryHook(
 				'ApiQuery::moduleManager',
-				function ( ApiModuleManager $moduleManager ) use ( $microtimeFunction ) {
+				static function ( ApiModuleManager $moduleManager ) use ( $microtimeFunction ) {
 					$moduleManager->addModule(
 						'languageinfo',
 						'meta',
 						[
 							'class' => ApiQueryLanguageinfo::class,
-							'factory' => function ( $parent, $name ) use ( $microtimeFunction ) {
+							'factory' => static function ( $parent, $name ) use ( $microtimeFunction ) {
 								$services = MediaWikiServices::getInstance();
 								return new ApiQueryLanguageinfo(
 									$parent,
@@ -122,7 +122,7 @@ class ApiQueryLanguageinfoTest extends ApiTestCase {
 
 	public function testContinuationNecessary() {
 		$time = 0;
-		$microtimeFunction = function () use ( &$time ) {
+		$microtimeFunction = static function () use ( &$time ) {
 			return $time += 0.75;
 		};
 
@@ -134,7 +134,7 @@ class ApiQueryLanguageinfoTest extends ApiTestCase {
 
 	public function testContinuationNotNecessary() {
 		$time = 0;
-		$microtimeFunction = function () use ( &$time ) {
+		$microtimeFunction = static function () use ( &$time ) {
 			return $time += 1.5;
 		};
 
@@ -147,7 +147,7 @@ class ApiQueryLanguageinfoTest extends ApiTestCase {
 
 	public function testContinuationInAlphabeticalOrderNotParameterOrder() {
 		$time = 0;
-		$microtimeFunction = function () use ( &$time ) {
+		$microtimeFunction = static function () use ( &$time ) {
 			return $time += 0.75;
 		};
 		$params = [ 'licode' => 'en|ru|zh|de|yue' ];
diff --git a/tests/phpunit/includes/api/query/ApiQuerySiteinfoTest.php b/tests/phpunit/includes/api/query/ApiQuerySiteinfoTest.php
index 2829a0cb89c..a3ac493eef5 100644
--- a/tests/phpunit/includes/api/query/ApiQuerySiteinfoTest.php
+++ b/tests/phpunit/includes/api/query/ApiQuerySiteinfoTest.php
@@ -283,7 +283,7 @@ class ApiQuerySiteinfoTest extends ApiTestCase {
 
 	public function testStatistics() {
 		$this->setTemporaryHook( 'APIQuerySiteInfoStatisticsInfo',
-			function ( &$data ) {
+			static function ( &$data ) {
 				$data['addedstats'] = 42;
 			}
 		);
@@ -666,7 +666,7 @@ class ApiQuerySiteinfoTest extends ApiTestCase {
 
 		// Make sure there's something to report on
 		$this->setTemporaryHook( 'somehook',
-			function () {
+			static function () {
 				return;
 			}
 		);
diff --git a/tests/phpunit/includes/api/query/ApiQueryTest.php b/tests/phpunit/includes/api/query/ApiQueryTest.php
index 4bb38ede150..f46853bb1e7 100644
--- a/tests/phpunit/includes/api/query/ApiQueryTest.php
+++ b/tests/phpunit/includes/api/query/ApiQueryTest.php
@@ -154,7 +154,7 @@ class ApiQueryTest extends ApiTestCase {
 		$this->insertPage( $title );
 
 		$this->setTemporaryHook( 'getUserPermissionsErrors',
-			function ( Title $page, &$user, $action, &$result ) use ( $title ) {
+			static function ( Title $page, &$user, $action, &$result ) use ( $title ) {
 				if ( $page->equals( $title ) && $action === 'read' ) {
 					$result = false;
 					return false;
diff --git a/tests/phpunit/includes/auth/AbstractPasswordPrimaryAuthenticationProviderTest.php b/tests/phpunit/includes/auth/AbstractPasswordPrimaryAuthenticationProviderTest.php
index de21bd1a1dd..4a2069ab3c5 100644
--- a/tests/phpunit/includes/auth/AbstractPasswordPrimaryAuthenticationProviderTest.php
+++ b/tests/phpunit/includes/auth/AbstractPasswordPrimaryAuthenticationProviderTest.php
@@ -97,7 +97,7 @@ class AbstractPasswordPrimaryAuthenticationProviderTest extends \MediaWikiIntegr
 					],
 				],
 				'checks' => [
-					'Check' => function () use ( &$uppCalled, &$uppStatus ) {
+					'Check' => static function () use ( &$uppCalled, &$uppStatus ) {
 						$uppCalled++;
 						return $uppStatus;
 					},
diff --git a/tests/phpunit/includes/auth/AuthManagerTest.php b/tests/phpunit/includes/auth/AuthManagerTest.php
index f9f904cd45e..60fb537b383 100644
--- a/tests/phpunit/includes/auth/AuthManagerTest.php
+++ b/tests/phpunit/includes/auth/AuthManagerTest.php
@@ -156,7 +156,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 		foreach ( [ 'preauth', 'primaryauth', 'secondaryauth' ] as $type ) {
 			$key = $type . 'Mocks';
 			foreach ( $this->$key as $mock ) {
-				$config[$type][$mock->getUniqueId()] = [ 'factory' => function () use ( $mock ) {
+				$config[$type][$mock->getUniqueId()] = [ 'factory' => static function () use ( $mock ) {
 					return $mock;
 				} ];
 			}
@@ -268,7 +268,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 				->will( $this->returnValue( $canChangeUser ) );
 		}
 		$this->config->set( 'SessionProviders', [
-			[ 'factory' => function () use ( $provider ) {
+			[ 'factory' => static function () use ( $provider ) {
 				return $provider;
 			} ],
 		] );
@@ -364,7 +364,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 			$mutableSession, [ 'provideSessionInfo' ]
 		);
 		$provider->expects( $this->any() )->method( 'provideSessionInfo' )
-			->will( $this->returnCallback( function () use ( $provider, &$provideUser ) {
+			->will( $this->returnCallback( static function () use ( $provider, &$provideUser ) {
 				return new SessionInfo( SessionInfo::MIN_PRIORITY, [
 					'provider' => $provider,
 					'id' => \DummySessionProvider::ID,
@@ -480,12 +480,12 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 				->with(
 					$this->anything(),
 					$this->anything(),
-					$this->callback( function ( $s ) use ( $session ) {
+					$this->callback( static function ( $s ) use ( $session ) {
 						return $s->getId() === $session->getId();
 					} ),
 					$mutableSession ? $this->equalTo( 500, 1 ) : $this->equalTo( -1 )
 				)
-				->will( $this->returnCallback( function ( &$v ) use ( $hook ) {
+				->will( $this->returnCallback( static function ( &$v ) use ( $hook ) {
 					$v = $hook;
 					return true;
 				} ) );
@@ -840,7 +840,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 		$this->request->getSession()->setSecret( 'AuthManager::authnState', 'test' );
 		$this->managerPriv->createdAccountAuthenticationRequests = [ $reqs[0] ];
 		$this->hook( 'UserLoggedIn', UserLoggedInHook::class, $this->once() )
-			->with( $this->callback( function ( $u ) use ( $user ) {
+			->with( $this->callback( static function ( $u ) use ( $user ) {
 				return $user->getId() === $u->getId() && $user->getName() === $u->getName();
 			} ) );
 		$this->hook( 'AuthManagerLoginAuthenticateAudit',
@@ -1085,7 +1085,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 				$response->status === AuthenticationResponse::PASS;
 			if ( $success ) {
 				$this->hook( 'UserLoggedIn', UserLoggedInHook::class, $this->once() )
-					->with( $this->callback( function ( $user ) use ( $id, $name ) {
+					->with( $this->callback( static function ( $user ) use ( $id, $name ) {
 						return $user->getId() === $id && $user->getName() === $name;
 					} ) );
 			} else {
@@ -1668,7 +1668,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 	public function testBeginAccountCreation() {
 		$creator = \User::newFromName( 'UTSysop' );
 		$userReq = new UsernameAuthenticationRequest;
-		$this->logger = new \TestLogger( false, function ( $message, $level ) {
+		$this->logger = new \TestLogger( false, static function ( $message, $level ) {
 			return $level === LogLevel::DEBUG ? null : $message;
 		} );
 		$this->initializeManager();
@@ -1817,7 +1817,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 	public function testContinueAccountCreation() {
 		$creator = \User::newFromName( 'UTSysop' );
 		$username = self::usernameForCreation();
-		$this->logger = new \TestLogger( false, function ( $message, $level ) {
+		$this->logger = new \TestLogger( false, static function ( $message, $level ) {
 			return $level === LogLevel::DEBUG ? null : $message;
 		} );
 		$this->initializeManager();
@@ -2093,7 +2093,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 			$mocks['secondary3'], $mocks['secondary'], $mocks['secondary2']
 		];
 
-		$this->logger = new \TestLogger( true, function ( $message, $level ) {
+		$this->logger = new \TestLogger( true, static function ( $message, $level ) {
 			return $level === LogLevel::DEBUG ? null : $message;
 		} );
 		$expectLog = [];
@@ -2134,7 +2134,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 				$created = true;
 				$this->hook( 'LocalUserCreated', LocalUserCreatedHook::class, $this->once() )
 					->with(
-						$this->callback( function ( $user ) use ( $username ) {
+						$this->callback( static function ( $user ) use ( $username ) {
 							return $user->getName() === $username;
 						} ),
 						$this->equalTo( false )
@@ -2483,11 +2483,11 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 
 		$good = StatusValue::newGood();
 		$ok = StatusValue::newFatal( 'ok' );
-		$callback = $this->callback( function ( $user ) use ( &$username, &$workaroundPHPUnitBug ) {
+		$callback = $this->callback( static function ( $user ) use ( &$username, &$workaroundPHPUnitBug ) {
 			return $workaroundPHPUnitBug || $user->getName() === $username;
 		} );
 		$callback2 = $this->callback(
-			function ( $source ) use ( &$expectedSource, &$workaroundPHPUnitBug ) {
+			static function ( $source ) use ( &$expectedSource, &$workaroundPHPUnitBug ) {
 				return $workaroundPHPUnitBug || $source === $expectedSource;
 			}
 		);
@@ -2540,7 +2540,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 		$this->initializeManager( true );
 		$session = $this->request->getSession();
 
-		$logger = new \TestLogger( true, function ( $m ) {
+		$logger = new \TestLogger( true, static function ( $m ) {
 			$m = str_replace( 'MediaWiki\\Auth\\AuthManager::autoCreateUser: ', '', $m );
 			return $m;
 		} );
@@ -2980,7 +2980,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 			$mocks[$key]->expects( $this->any() )->method( 'getUniqueId' )
 				->will( $this->returnValue( $key ) );
 			$mocks[$key]->expects( $this->any() )->method( 'getAuthenticationRequests' )
-				->will( $this->returnCallback( function ( $action ) use ( $key, $makeReq ) {
+				->will( $this->returnCallback( static function ( $action ) use ( $key, $makeReq ) {
 					return [ $makeReq( "$key-$action" ), $makeReq( 'generic' ) ];
 				} ) );
 			$mocks[$key]->expects( $this->any() )->method( 'providerAllowsAuthenticationDataChange' )
@@ -3005,7 +3005,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 			$mocks["primary-$type"]->expects( $this->any() )->method( 'accountCreationType' )
 				->will( $this->returnValue( $type ) );
 			$mocks["primary-$type"]->expects( $this->any() )->method( 'getAuthenticationRequests' )
-				->will( $this->returnCallback( function ( $action ) use ( $type, $makeReq ) {
+				->will( $this->returnCallback( static function ( $action ) use ( $type, $makeReq ) {
 					return [ $makeReq( "primary-$type-$action" ), $makeReq( 'generic' ) ];
 				} ) );
 			$mocks["primary-$type"]->expects( $this->any() )
@@ -3028,7 +3028,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 			->will( $this->returnValue( [] ) );
 		$mocks['primary2']->expects( $this->any() )
 			->method( 'providerAllowsAuthenticationDataChange' )
-			->will( $this->returnCallback( function ( $req ) use ( $good ) {
+			->will( $this->returnCallback( static function ( $req ) use ( $good ) {
 				return $req->key === 'generic' ? StatusValue::newFatal( 'no' ) : $good;
 			} ) );
 		$this->primaryauthMocks[] = $mocks['primary2'];
@@ -3187,7 +3187,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 		$primary1->expects( $this->any() )->method( 'accountCreationType' )
 			->will( $this->returnValue( PrimaryAuthenticationProvider::TYPE_CREATE ) );
 		$primary1->expects( $this->any() )->method( 'getAuthenticationRequests' )
-			->will( $this->returnCallback( function ( $action ) use ( $makeReq ) {
+			->will( $this->returnCallback( static function ( $action ) use ( $makeReq ) {
 				return [
 					$makeReq( "primary-shared", AuthenticationRequest::REQUIRED ),
 					$makeReq( "required", AuthenticationRequest::REQUIRED ),
@@ -3204,7 +3204,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 		$primary2->expects( $this->any() )->method( 'accountCreationType' )
 			->will( $this->returnValue( PrimaryAuthenticationProvider::TYPE_CREATE ) );
 		$primary2->expects( $this->any() )->method( 'getAuthenticationRequests' )
-			->will( $this->returnCallback( function ( $action ) use ( $makeReq ) {
+			->will( $this->returnCallback( static function ( $action ) use ( $makeReq ) {
 				return [
 					$makeReq( "primary-shared", AuthenticationRequest::REQUIRED ),
 					$makeReq( "required2", AuthenticationRequest::REQUIRED ),
@@ -3216,7 +3216,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 		$secondary->expects( $this->any() )->method( 'getUniqueId' )
 			->will( $this->returnValue( 'secondary' ) );
 		$secondary->expects( $this->any() )->method( 'getAuthenticationRequests' )
-			->will( $this->returnCallback( function ( $action ) use ( $makeReq ) {
+			->will( $this->returnCallback( static function ( $action ) use ( $makeReq ) {
 				return [
 					$makeReq( "foo", AuthenticationRequest::OPTIONAL ),
 					$makeReq( "bar", AuthenticationRequest::REQUIRED ),
@@ -3274,7 +3274,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 			$mocks[$key]->expects( $this->any() )->method( 'getUniqueId' )
 				->will( $this->returnValue( $key ) );
 			$mocks[$key]->expects( $this->any() )->method( 'providerAllowsPropertyChange' )
-				->will( $this->returnCallback( function ( $prop ) use ( $key ) {
+				->will( $this->returnCallback( static function ( $prop ) use ( $key ) {
 					return $prop !== $key;
 				} ) );
 		}
@@ -3326,7 +3326,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 		$this->assertSame( 0, \User::newFromName( $username )->getId(),
 			'sanity check' );
 
-		$callback = $this->callback( function ( $user ) use ( $username ) {
+		$callback = $this->callback( static function ( $user ) use ( $username ) {
 			return $user->getName() === $username;
 		} );
 
@@ -3593,7 +3593,7 @@ class AuthManagerTest extends \MediaWikiIntegrationTestCase {
 
 		$this->preauthMocks = [ $mocks['pre'], $mocks['pre2'] ];
 		$this->primaryauthMocks = [ $mocks['primary3'], $mocks['primary2'], $mocks['primary'] ];
-		$this->logger = new \TestLogger( true, function ( $message, $level ) {
+		$this->logger = new \TestLogger( true, static function ( $message, $level ) {
 			return $level === LogLevel::DEBUG ? null : $message;
 		} );
 		$this->initializeManager( true );
diff --git a/tests/phpunit/includes/auth/ConfirmLinkSecondaryAuthenticationProviderTest.php b/tests/phpunit/includes/auth/ConfirmLinkSecondaryAuthenticationProviderTest.php
index 722ca29c97e..408a4e966c4 100644
--- a/tests/phpunit/includes/auth/ConfirmLinkSecondaryAuthenticationProviderTest.php
+++ b/tests/phpunit/includes/auth/ConfirmLinkSecondaryAuthenticationProviderTest.php
@@ -152,7 +152,7 @@ class ConfirmLinkSecondaryAuthenticationProviderTest extends \MediaWikiIntegrati
 			] )
 			->getMock();
 		$manager->expects( $this->any() )->method( 'allowsAuthenticationDataChange' )
-			->will( $this->returnCallback( function ( $req ) {
+			->will( $this->returnCallback( static function ( $req ) {
 				return $req->getUniqueId() !== 'BadReq'
 					? \StatusValue::newGood()
 					: \StatusValue::newFatal( 'no' );
@@ -219,12 +219,12 @@ class ConfirmLinkSecondaryAuthenticationProviderTest extends \MediaWikiIntegrati
 			->getMock();
 		$provider->expects( $this->never() )->method( 'beginLinkAttempt' );
 		$provider->expects( $this->any() )->method( 'providerAllowsAuthenticationDataChange' )
-			->will( $this->returnCallback( function ( $req ) use ( $reqs ) {
+			->will( $this->returnCallback( static function ( $req ) use ( $reqs ) {
 				return $req->getUniqueId() === 'Request3'
 					? \StatusValue::newFatal( 'foo' ) : \StatusValue::newGood();
 			} ) );
 		$provider->expects( $this->any() )->method( 'providerChangeAuthenticationData' )
-			->will( $this->returnCallback( function ( $req ) use ( &$done ) {
+			->will( $this->returnCallback( static function ( $req ) use ( &$done ) {
 				$done[$req->id] = true;
 			} ) );
 		$config = new \HashConfig( [
@@ -232,7 +232,7 @@ class ConfirmLinkSecondaryAuthenticationProviderTest extends \MediaWikiIntegrati
 				'preauth' => [],
 				'primaryauth' => [],
 				'secondaryauth' => [
-					[ 'factory' => function () use ( $provider ) {
+					[ 'factory' => static function () use ( $provider ) {
 						return $provider;
 					} ],
 				],
diff --git a/tests/phpunit/includes/auth/LocalPasswordPrimaryAuthenticationProviderTest.php b/tests/phpunit/includes/auth/LocalPasswordPrimaryAuthenticationProviderTest.php
index c700815fd09..a0b32c63a25 100644
--- a/tests/phpunit/includes/auth/LocalPasswordPrimaryAuthenticationProviderTest.php
+++ b/tests/phpunit/includes/auth/LocalPasswordPrimaryAuthenticationProviderTest.php
@@ -460,7 +460,7 @@ class LocalPasswordPrimaryAuthenticationProviderTest extends \MediaWikiIntegrati
 		$oldExpiry = $dbw->selectField( 'user', 'user_password_expires', [ 'user_name' => $cuser ] );
 
 		$this->mergeMwGlobalArrayValue( 'wgHooks', [
-			'ResetPasswordExpiration' => [ function ( $user, &$expires ) {
+			'ResetPasswordExpiration' => [ static function ( $user, &$expires ) {
 				$expires = '30001231235959';
 			} ]
 		] );
diff --git a/tests/phpunit/includes/auth/ResetPasswordSecondaryAuthenticationProviderTest.php b/tests/phpunit/includes/auth/ResetPasswordSecondaryAuthenticationProviderTest.php
index dee22661ade..3bfd0733be7 100644
--- a/tests/phpunit/includes/auth/ResetPasswordSecondaryAuthenticationProviderTest.php
+++ b/tests/phpunit/includes/auth/ResetPasswordSecondaryAuthenticationProviderTest.php
@@ -83,7 +83,7 @@ class ResetPasswordSecondaryAuthenticationProviderTest extends \MediaWikiIntegra
 				'preauth' => [],
 				'primaryauth' => [],
 				'secondaryauth' => [
-					[ 'factory' => function () use ( $provider ) {
+					[ 'factory' => static function () use ( $provider ) {
 						return $provider;
 					} ],
 				],
diff --git a/tests/phpunit/includes/auth/TemporaryPasswordPrimaryAuthenticationProviderTest.php b/tests/phpunit/includes/auth/TemporaryPasswordPrimaryAuthenticationProviderTest.php
index 93d1d7fbe14..412cc9296a4 100644
--- a/tests/phpunit/includes/auth/TemporaryPasswordPrimaryAuthenticationProviderTest.php
+++ b/tests/phpunit/includes/auth/TemporaryPasswordPrimaryAuthenticationProviderTest.php
@@ -430,7 +430,7 @@ class TemporaryPasswordPrimaryAuthenticationProviderTest extends \MediaWikiInteg
 
 		$dbw = wfGetDB( DB_MASTER );
 		$oldHash = $dbw->selectField( 'user', 'user_newpassword', [ 'user_name' => $cuser ] );
-		$cb = new ScopedCallback( function () use ( $dbw, $cuser, $oldHash ) {
+		$cb = new ScopedCallback( static function () use ( $dbw, $cuser, $oldHash ) {
 			$dbw->update( 'user', [ 'user_newpassword' => $oldHash ], [ 'user_name' => $cuser ] );
 		} );
 
diff --git a/tests/phpunit/includes/block/BlockManagerTest.php b/tests/phpunit/includes/block/BlockManagerTest.php
index 9bd60388cd1..1171e481b44 100644
--- a/tests/phpunit/includes/block/BlockManagerTest.php
+++ b/tests/phpunit/includes/block/BlockManagerTest.php
@@ -79,7 +79,7 @@ class BlockManagerTest extends MediaWikiIntegrationTestCase {
 		$onUserGetRightsCalled = false;
 		$this->setTemporaryHook(
 			'UserGetRights',
-			function ( $user, &$rights ) use ( &$onUserGetRightsCalled ) {
+			static function ( $user, &$rights ) use ( &$onUserGetRightsCalled ) {
 				$onUserGetRightsCalled = true;
 				$rights[] = 'ipblock-exempt';
 				return true;
@@ -89,7 +89,7 @@ class BlockManagerTest extends MediaWikiIntegrationTestCase {
 		$onGetUserBlockIP = false;
 		$this->setTemporaryHook(
 			'GetUserBlock',
-			function ( $user, $ip, &$block ) use ( &$onGetUserBlockCalled, &$onGetUserBlockIP ) {
+			static function ( $user, $ip, &$block ) use ( &$onGetUserBlockCalled, &$onGetUserBlockIP ) {
 				$onGetUserBlockCalled = true;
 				$onGetUserBlockIP = $ip;
 				return true;
diff --git a/tests/phpunit/includes/cache/LinkBatchTest.php b/tests/phpunit/includes/cache/LinkBatchTest.php
index 447d25b3866..c62bda1550a 100644
--- a/tests/phpunit/includes/cache/LinkBatchTest.php
+++ b/tests/phpunit/includes/cache/LinkBatchTest.php
@@ -137,13 +137,13 @@ class LinkBatchTest extends MediaWikiIntegrationTestCase {
 
 		$cache->expects( $this->exactly( 2 ) )
 			->method( 'addGoodLinkObjFromRow' )
-			->willReturnCallback( function ( TitleValue $title, $row ) use ( &$good ) {
+			->willReturnCallback( static function ( TitleValue $title, $row ) use ( &$good ) {
 				$good["$title"] = $title;
 			} );
 
 		$cache->expects( $this->exactly( 2 ) )
 			->method( 'addBadLinkObj' )
-			->willReturnCallback( function ( TitleValue $title ) use ( &$bad ) {
+			->willReturnCallback( static function ( TitleValue $title ) use ( &$bad ) {
 				$bad["$title"] = $title;
 			} );
 
diff --git a/tests/phpunit/includes/cache/LocalisationCacheTest.php b/tests/phpunit/includes/cache/LocalisationCacheTest.php
index 87d7fe4cff8..707961a09ce 100644
--- a/tests/phpunit/includes/cache/LocalisationCacheTest.php
+++ b/tests/phpunit/includes/cache/LocalisationCacheTest.php
@@ -28,13 +28,13 @@ class LocalisationCacheTest extends MediaWikiIntegrationTestCase {
 
 		$mockLangNameUtils = $this->createMock( LanguageNameUtils::class );
 		$mockLangNameUtils->method( 'isValidBuiltInCode' )->will( $this->returnCallback(
-			function ( $code ) {
+			static function ( $code ) {
 				// Copy-paste, but it's only one line
 				return (bool)preg_match( '/^[a-z0-9-]{2,}$/', $code );
 			}
 		) );
 		$mockLangNameUtils->method( 'isSupportedLanguage' )->will( $this->returnCallback(
-			function ( $code ) {
+			static function ( $code ) {
 				return in_array( $code, [
 					'ar',
 					'arz',
@@ -47,7 +47,7 @@ class LocalisationCacheTest extends MediaWikiIntegrationTestCase {
 			}
 		) );
 		$mockLangNameUtils->method( 'getMessagesFileName' )->will( $this->returnCallback(
-			function ( $code ) {
+			static function ( $code ) {
 				global $IP;
 				$code = str_replace( '-', '_', ucfirst( $code ) );
 				return "$IP/languages/messages/Messages$code.php";
@@ -131,7 +131,7 @@ class LocalisationCacheTest extends MediaWikiIntegrationTestCase {
 
 		$lc = $this->getMockLocalisationCache( [
 			'LocalisationCacheRecacheFallback' => [
-				function (
+				static function (
 					LocalisationCache $lc,
 					$code,
 					array &$cache
diff --git a/tests/phpunit/includes/changes/EnhancedChangesListTest.php b/tests/phpunit/includes/changes/EnhancedChangesListTest.php
index 53d3f49f826..0a0f29a759c 100644
--- a/tests/phpunit/includes/changes/EnhancedChangesListTest.php
+++ b/tests/phpunit/includes/changes/EnhancedChangesListTest.php
@@ -96,13 +96,13 @@ class EnhancedChangesListTest extends MediaWikiLangTestCase {
 			return 'Hello world prefix';
 		} );
 
-		$this->setTemporaryHook( 'EnhancedChangesListModifyLineData', function (
+		$this->setTemporaryHook( 'EnhancedChangesListModifyLineData', static function (
 			$enhancedChangesList, &$data, $block, $rc, &$classes, &$attribs
 		) {
 			$data['recentChangesFlags']['minor'] = 1;
 		} );
 
-		$this->setTemporaryHook( 'EnhancedChangesListModifyBlockLineData', function (
+		$this->setTemporaryHook( 'EnhancedChangesListModifyBlockLineData', static function (
 			$enhancedChangesList, &$data, $rcObj
 		) {
 			$data['recentChangesFlags']['bot'] = 1;
diff --git a/tests/phpunit/includes/changes/OldChangesListTest.php b/tests/phpunit/includes/changes/OldChangesListTest.php
index 8e78777f06a..ace3cee61a3 100644
--- a/tests/phpunit/includes/changes/OldChangesListTest.php
+++ b/tests/phpunit/includes/changes/OldChangesListTest.php
@@ -123,7 +123,7 @@ class OldChangesListTest extends MediaWikiLangTestCase {
 		$recentChange = $this->getEditChange();
 		$recentChange->mAttribs['ts_tags'] = 'vandalism,newbie';
 
-		$this->setTemporaryHook( 'OldChangesListRecentChangesLine', function (
+		$this->setTemporaryHook( 'OldChangesListRecentChangesLine', static function (
 			$oldChangesList, &$html, $rc, $classes, $attribs
 		) {
 			$html = $html . '/<div>Additional change line </div>/';
diff --git a/tests/phpunit/includes/config/ConfigFactoryTest.php b/tests/phpunit/includes/config/ConfigFactoryTest.php
index 6a6c2662ad3..34df7f235f4 100644
--- a/tests/phpunit/includes/config/ConfigFactoryTest.php
+++ b/tests/phpunit/includes/config/ConfigFactoryTest.php
@@ -72,7 +72,7 @@ class ConfigFactoryTest extends \MediaWikiIntegrationTestCase {
 		// define new config instance
 		$newFactory = new ConfigFactory();
 		$newFactory->register( 'foo', 'GlobalVarConfig::newInstance' );
-		$newFactory->register( 'bar', function () {
+		$newFactory->register( 'bar', static function () {
 			return new HashConfig();
 		} );
 
@@ -148,7 +148,7 @@ class ConfigFactoryTest extends \MediaWikiIntegrationTestCase {
 	 */
 	public function testMakeConfigWithInvalidCallback() {
 		$factory = new ConfigFactory();
-		$factory->register( 'unittest', function () {
+		$factory->register( 'unittest', static function () {
 			return true; // Not a Config object
 		} );
 		$this->expectException( UnexpectedValueException::class );
diff --git a/tests/phpunit/includes/content/ContentHandlerTest.php b/tests/phpunit/includes/content/ContentHandlerTest.php
index e0b225967a9..0b32dcbc6d9 100644
--- a/tests/phpunit/includes/content/ContentHandlerTest.php
+++ b/tests/phpunit/includes/content/ContentHandlerTest.php
@@ -29,7 +29,7 @@ class ContentHandlerTest extends MediaWikiIntegrationTestCase {
 				CONTENT_MODEL_CSS => CssContentHandler::class,
 				CONTENT_MODEL_TEXT => TextContentHandler::class,
 				'testing' => DummyContentHandlerForTesting::class,
-				'testing-callbacks' => function ( $modelId ) {
+				'testing-callbacks' => static function ( $modelId ) {
 					return new DummyContentHandlerForTesting( $modelId );
 				}
 			],
@@ -428,7 +428,7 @@ class ContentHandlerTest extends MediaWikiIntegrationTestCase {
 
 		$searchEngine->expects( $this->any() )
 			->method( 'makeSearchFieldMapping' )
-			->will( $this->returnCallback( function ( $name, $type ) {
+			->will( $this->returnCallback( static function ( $name, $type ) {
 					return new DummySearchIndexFieldDefinition( $name, $type );
 			} ) );
 
@@ -444,7 +444,7 @@ class ContentHandlerTest extends MediaWikiIntegrationTestCase {
 		$page = new WikiPage( $title );
 
 		$this->setTemporaryHook( 'SearchDataForIndex',
-			function (
+			static function (
 				&$fields,
 				ContentHandler $handler,
 				WikiPage $page,
@@ -480,7 +480,7 @@ class ContentHandlerTest extends MediaWikiIntegrationTestCase {
 	 * @covers ContentHandler::getContentModels
 	 */
 	public function testGetContentModelsHook() {
-		$this->setTemporaryHook( 'GetContentModels', function ( &$models ) {
+		$this->setTemporaryHook( 'GetContentModels', static function ( &$models ) {
 			$models[] = 'Ferrari';
 		} );
 		$this->assertContains( 'Ferrari', ContentHandler::getContentModels() );
@@ -600,7 +600,7 @@ class ContentHandlerTest extends MediaWikiIntegrationTestCase {
 			->disableOriginalConstructor()
 			->getMockForAbstractClass();
 		$this->setTemporaryHook( 'GetSlotDiffRenderer',
-			function ( $handler, &$slotDiffRenderer ) use ( $customSlotDiffRenderer2 ) {
+			static function ( $handler, &$slotDiffRenderer ) use ( $customSlotDiffRenderer2 ) {
 				$slotDiffRenderer = $customSlotDiffRenderer2;
 			} );
 
diff --git a/tests/phpunit/includes/content/ContentModelChangeTest.php b/tests/phpunit/includes/content/ContentModelChangeTest.php
index 55e2f693d15..2e34263428f 100644
--- a/tests/phpunit/includes/content/ContentModelChangeTest.php
+++ b/tests/phpunit/includes/content/ContentModelChangeTest.php
@@ -138,7 +138,7 @@ class ContentModelChangeTest extends MediaWikiIntegrationTestCase {
 		);
 
 		$this->setTemporaryHook( 'EditFilterMergedContent',
-			function ( $unused1, $unused2, Status $status ) use ( $customMessage ) {
+			static function ( $unused1, $unused2, Status $status ) use ( $customMessage ) {
 				if ( $customMessage !== false ) {
 					$status->fatal( $customMessage );
 				}
@@ -190,7 +190,7 @@ class ContentModelChangeTest extends MediaWikiIntegrationTestCase {
 		);
 
 		$this->setTemporaryHook( 'ContentModelCanBeUsedOn',
-			function ( $unused1, $unused2, &$ok ) {
+			static function ( $unused1, $unused2, &$ok ) {
 				$ok = false;
 				return false;
 			}
@@ -301,40 +301,40 @@ class ContentModelChangeTest extends MediaWikiIntegrationTestCase {
 			->withConsecutive(
 				[
 					$this->equalTo( 'editcontentmodel' ),
-					$this->callback( function ( User $userInMock ) use ( $user ) {
+					$this->callback( static function ( User $userInMock ) use ( $user ) {
 						return $user->equals( $userInMock );
 					} ),
-					$this->callback( function ( Title $titleInMock ) use ( $title, $currentContentModel ) {
+					$this->callback( static function ( Title $titleInMock ) use ( $title, $currentContentModel ) {
 						return $title->equals( $titleInMock ) &&
 							$titleInMock->hasContentModel( $currentContentModel );
 					} )
 				],
 				[
 					$this->equalTo( 'edit' ),
-					$this->callback( function ( User $userInMock ) use ( $user ) {
+					$this->callback( static function ( User $userInMock ) use ( $user ) {
 						return $user->equals( $userInMock );
 					} ),
-					$this->callback( function ( Title $titleInMock ) use ( $title, $currentContentModel ) {
+					$this->callback( static function ( Title $titleInMock ) use ( $title, $currentContentModel ) {
 						return $title->equals( $titleInMock ) &&
 							$titleInMock->hasContentModel( $currentContentModel );
 					} )
 				],
 				[
 					$this->equalTo( 'editcontentmodel' ),
-					$this->callback( function ( User $userInMock ) use ( $user ) {
+					$this->callback( static function ( User $userInMock ) use ( $user ) {
 						return $user->equals( $userInMock );
 					} ),
-					$this->callback( function ( Title $titleInMock ) use ( $title, $newContentModel ) {
+					$this->callback( static function ( Title $titleInMock ) use ( $title, $newContentModel ) {
 						return $title->equals( $titleInMock ) &&
 							$titleInMock->hasContentModel( $newContentModel );
 					} )
 				],
 				[
 					$this->equalTo( 'edit' ),
-					$this->callback( function ( User $userInMock ) use ( $user ) {
+					$this->callback( static function ( User $userInMock ) use ( $user ) {
 						return $user->equals( $userInMock );
 					} ),
-					$this->callback( function ( Title $titleInMock ) use ( $title, $newContentModel ) {
+					$this->callback( static function ( Title $titleInMock ) use ( $title, $newContentModel ) {
 						return $title->equals( $titleInMock ) &&
 							$titleInMock->hasContentModel( $newContentModel );
 					} )
diff --git a/tests/phpunit/includes/content/ObjectFactoryMakeContentHandlerWithSpecsToTest.php b/tests/phpunit/includes/content/ObjectFactoryMakeContentHandlerWithSpecsToTest.php
index 759909a7005..f337404b433 100644
--- a/tests/phpunit/includes/content/ObjectFactoryMakeContentHandlerWithSpecsToTest.php
+++ b/tests/phpunit/includes/content/ObjectFactoryMakeContentHandlerWithSpecsToTest.php
@@ -44,7 +44,7 @@ class ObjectFactoryMakeContentHandlerWithSpecsToTest extends MediaWikiIntegratio
 			'typical list' => [
 				[
 					'ExistClassName' => DummyContentHandlerForTesting::class,
-					'ExistCallbackWithExistClassName' => function ( $modelID ) {
+					'ExistCallbackWithExistClassName' => static function ( $modelID ) {
 						return new DummyContentHandlerForTesting( $modelID );
 					},
 				],
@@ -82,13 +82,13 @@ class ObjectFactoryMakeContentHandlerWithSpecsToTest extends MediaWikiIntegratio
 		return [
 			'UnexpectedValueException with wrong specs result' => [
 				[
-					'ExistCallbackWithWrongType' => function () {
+					'ExistCallbackWithWrongType' => static function () {
 						return true;
 					},
-					'ExistCallbackWithNull' => function () {
+					'ExistCallbackWithNull' => static function () {
 						return null;
 					},
-					'ExistCallbackWithEmptyString' => function () {
+					'ExistCallbackWithEmptyString' => static function () {
 						return '';
 					},
 					'WrongClassName' => self::class,
@@ -108,7 +108,7 @@ class ObjectFactoryMakeContentHandlerWithSpecsToTest extends MediaWikiIntegratio
 			],
 			'Error expected' => [
 				[
-					'ExistCallbackWithNotExistClassName' => function () {
+					'ExistCallbackWithNotExistClassName' => static function () {
 						return \ClassNameNotExist();
 					},
 				],
diff --git a/tests/phpunit/includes/content/RegistrationContentHandlerFactoryToMediaWikiServicesTest.php b/tests/phpunit/includes/content/RegistrationContentHandlerFactoryToMediaWikiServicesTest.php
index 51fc99e09e7..fd261aa25c9 100644
--- a/tests/phpunit/includes/content/RegistrationContentHandlerFactoryToMediaWikiServicesTest.php
+++ b/tests/phpunit/includes/content/RegistrationContentHandlerFactoryToMediaWikiServicesTest.php
@@ -18,7 +18,7 @@ class RegistrationContentHandlerFactoryToMediaWikiServicesTest extends MediaWiki
 				CONTENT_MODEL_CSS => CssContentHandler::class,
 				CONTENT_MODEL_TEXT => TextContentHandler::class,
 				'testing' => DummyContentHandlerForTesting::class,
-				'testing-callbacks' => function ( $modelId ) {
+				'testing-callbacks' => static function ( $modelId ) {
 					return new DummyContentHandlerForTesting( $modelId );
 				},
 			],
diff --git a/tests/phpunit/includes/content/WikitextContentTest.php b/tests/phpunit/includes/content/WikitextContentTest.php
index 2d7175cba9a..c0b6d4774e9 100644
--- a/tests/phpunit/includes/content/WikitextContentTest.php
+++ b/tests/phpunit/includes/content/WikitextContentTest.php
@@ -373,7 +373,7 @@ just a test"
 		$redirectTarget = null;
 		$this->mergeMwGlobalArrayValue( 'wgHooks', [
 			'InternalParseBeforeLinks' => [
-				function ( Parser $parser, $text, $stripState ) use ( &$wikitext, &$redirectTarget ) {
+				static function ( Parser $parser, $text, $stripState ) use ( &$wikitext, &$redirectTarget ) {
 					$wikitext = $text;
 					$redirectTarget = $parser->getOptions()->getRedirectTarget();
 				}
diff --git a/tests/phpunit/includes/db/DatabaseTestHelper.php b/tests/phpunit/includes/db/DatabaseTestHelper.php
index 83f68cdcf8c..a192846135c 100644
--- a/tests/phpunit/includes/db/DatabaseTestHelper.php
+++ b/tests/phpunit/includes/db/DatabaseTestHelper.php
@@ -65,10 +65,10 @@ class DatabaseTestHelper extends Database {
 			'connLogger' => new NullLogger(),
 			'queryLogger' => new NullLogger(),
 			'replLogger' => new NullLogger(),
-			'errorLogger' => function ( Exception $e ) {
+			'errorLogger' => static function ( Exception $e ) {
 				wfWarn( get_class( $e ) . ": {$e->getMessage()}" );
 			},
-			'deprecationLogger' => function ( $msg ) {
+			'deprecationLogger' => static function ( $msg ) {
 				wfWarn( $msg );
 			}
 		] );
diff --git a/tests/phpunit/includes/db/LBFactoryTest.php b/tests/phpunit/includes/db/LBFactoryTest.php
index fe7453a71fa..bea6eb3c13a 100644
--- a/tests/phpunit/includes/db/LBFactoryTest.php
+++ b/tests/phpunit/includes/db/LBFactoryTest.php
@@ -151,7 +151,7 @@ class LBFactoryTest extends MediaWikiIntegrationTestCase {
 		$called = 0;
 		$countLBsFunc = static function ( LBFactoryMulti $factory ) {
 			$count = 0;
-			$factory->forEachLB( function () use ( &$count ) {
+			$factory->forEachLB( static function () use ( &$count ) {
 				++$count;
 			} );
 
@@ -165,7 +165,7 @@ class LBFactoryTest extends MediaWikiIntegrationTestCase {
 		// Test that LoadBalancer instances made during pre-commit callbacks in do not
 		// throw DBTransactionError due to transaction ROUND_* stages being mismatched.
 		$factory->beginMasterChanges( __METHOD__ );
-		$dbw->onTransactionPreCommitOrIdle( function () use ( $factory, &$called ) {
+		$dbw->onTransactionPreCommitOrIdle( static function () use ( $factory, &$called ) {
 			++$called;
 			// Trigger s1 LoadBalancer instantiation during "finalize" stage.
 			// There is no s1wiki DB to select so it is not in getConnection(),
@@ -188,7 +188,7 @@ class LBFactoryTest extends MediaWikiIntegrationTestCase {
 		// DBTransactionError due to transaction ROUND_* stages being mismatched.
 		$factory->beginMasterChanges( __METHOD__ );
 		$dbw->query( "SELECT 1 as t", __METHOD__ );
-		$dbw->onTransactionResolution( function () use ( $factory, &$called ) {
+		$dbw->onTransactionResolution( static function () use ( $factory, &$called ) {
 			++$called;
 			// Trigger s1 LoadBalancer instantiation during "finalize" stage.
 			// There is no s1wiki DB to select so it is not in getConnection(),
@@ -205,7 +205,7 @@ class LBFactoryTest extends MediaWikiIntegrationTestCase {
 		$dbw = $factory->getMainLB()->getConnection( DB_MASTER );
 		// DBTransactionError should not be thrown
 		$ran = 0;
-		$dbw->onTransactionPreCommitOrIdle( function () use ( &$ran ) {
+		$dbw->onTransactionPreCommitOrIdle( static function () use ( &$ran ) {
 			++$ran;
 		} );
 		$factory->commitAll( __METHOD__ );
@@ -278,7 +278,7 @@ class LBFactoryTest extends MediaWikiIntegrationTestCase {
 		$lb1->method( 'hasStreamingReplicaServers' )->willReturn( true );
 		$lb1->method( 'getAnyOpenConnection' )->willReturn( $mockDB1 );
 		$lb1->method( 'hasOrMadeRecentMasterChanges' )->will( $this->returnCallback(
-				function () use ( $mockDB1 ) {
+				static function () use ( $mockDB1 ) {
 					$p = 0;
 					$p |= $mockDB1->writesOrCallbacksPending();
 					$p |= $mockDB1->lastDoneWrites();
@@ -307,7 +307,7 @@ class LBFactoryTest extends MediaWikiIntegrationTestCase {
 		$lb2->method( 'hasStreamingReplicaServers' )->willReturn( true );
 		$lb2->method( 'getAnyOpenConnection' )->willReturn( $mockDB2 );
 		$lb2->method( 'hasOrMadeRecentMasterChanges' )->will( $this->returnCallback(
-			function () use ( $mockDB2 ) {
+			static function () use ( $mockDB2 ) {
 				$p = 0;
 				$p |= $mockDB2->writesOrCallbacksPending();
 				$p |= $mockDB2->lastDoneWrites();
@@ -689,7 +689,7 @@ class LBFactoryTest extends MediaWikiIntegrationTestCase {
 		$factory->redefineLocalDomain( $domain );
 
 		$n = 0;
-		$lb->forEachOpenConnection( function () use ( &$n ) {
+		$lb->forEachOpenConnection( static function () use ( &$n ) {
 			++$n;
 		} );
 		$this->assertSame( 0, $n, "Connections closed" );
diff --git a/tests/phpunit/includes/db/LoadBalancerTest.php b/tests/phpunit/includes/db/LoadBalancerTest.php
index 44b14ff1ffe..1b63ab13e35 100644
--- a/tests/phpunit/includes/db/LoadBalancerTest.php
+++ b/tests/phpunit/includes/db/LoadBalancerTest.php
@@ -68,7 +68,7 @@ class LoadBalancerTest extends MediaWikiIntegrationTestCase {
 			'servers' => [ $this->makeServerConfig( DBO_TRX ) ],
 			'queryLogger' => MediaWiki\Logger\LoggerFactory::getInstance( 'DBQuery' ),
 			'localDomain' => new DatabaseDomain( $wgDBname, null, $this->dbPrefix() ),
-			'chronologyCallback' => function () use ( &$called ) {
+			'chronologyCallback' => static function () use ( &$called ) {
 				$called = true;
 			}
 		] );
@@ -521,25 +521,25 @@ class LoadBalancerTest extends MediaWikiIntegrationTestCase {
 		$conn2 = $lb->openConnection( $lb->getWriterIndex(), '' );
 
 		$count = 0;
-		$lb->forEachOpenMasterConnection( function () use ( &$count ) {
+		$lb->forEachOpenMasterConnection( static function () use ( &$count ) {
 			++$count;
 		} );
 		$this->assertEquals( 2, $count, 'Connection handle count' );
 
 		$tlCalls = 0;
-		$lb->setTransactionListener( 'test-listener', function () use ( &$tlCalls ) {
+		$lb->setTransactionListener( 'test-listener', static function () use ( &$tlCalls ) {
 			++$tlCalls;
 		} );
 
 		$lb->beginMasterChanges( __METHOD__ );
 		$bc = array_fill_keys( [ 'a', 'b', 'c', 'd' ], 0 );
-		$conn1->onTransactionPreCommitOrIdle( function () use ( &$bc, $conn1, $conn2 ) {
+		$conn1->onTransactionPreCommitOrIdle( static function () use ( &$bc, $conn1, $conn2 ) {
 			$bc['a'] = 1;
-			$conn2->onTransactionPreCommitOrIdle( function () use ( &$bc, $conn1, $conn2 ) {
+			$conn2->onTransactionPreCommitOrIdle( static function () use ( &$bc, $conn1, $conn2 ) {
 				$bc['b'] = 1;
-				$conn1->onTransactionPreCommitOrIdle( function () use ( &$bc, $conn1, $conn2 ) {
+				$conn1->onTransactionPreCommitOrIdle( static function () use ( &$bc, $conn1, $conn2 ) {
 					$bc['c'] = 1;
-					$conn1->onTransactionPreCommitOrIdle( function () use ( &$bc, $conn1, $conn2 ) {
+					$conn1->onTransactionPreCommitOrIdle( static function () use ( &$bc, $conn1, $conn2 ) {
 						$bc['d'] = 1;
 					} );
 				} );
@@ -557,13 +557,13 @@ class LoadBalancerTest extends MediaWikiIntegrationTestCase {
 		$tlCalls = 0;
 		$lb->beginMasterChanges( __METHOD__ );
 		$ac = array_fill_keys( [ 'a', 'b', 'c', 'd' ], 0 );
-		$conn1->onTransactionCommitOrIdle( function () use ( &$ac, $conn1, $conn2 ) {
+		$conn1->onTransactionCommitOrIdle( static function () use ( &$ac, $conn1, $conn2 ) {
 			$ac['a'] = 1;
-			$conn2->onTransactionCommitOrIdle( function () use ( &$ac, $conn1, $conn2 ) {
+			$conn2->onTransactionCommitOrIdle( static function () use ( &$ac, $conn1, $conn2 ) {
 				$ac['b'] = 1;
-				$conn1->onTransactionCommitOrIdle( function () use ( &$ac, $conn1, $conn2 ) {
+				$conn1->onTransactionCommitOrIdle( static function () use ( &$ac, $conn1, $conn2 ) {
 					$ac['c'] = 1;
-					$conn1->onTransactionCommitOrIdle( function () use ( &$ac, $conn1, $conn2 ) {
+					$conn1->onTransactionCommitOrIdle( static function () use ( &$ac, $conn1, $conn2 ) {
 						$ac['d'] = 1;
 					} );
 				} );
diff --git a/tests/phpunit/includes/debug/TestDeprecatedClass.php b/tests/phpunit/includes/debug/TestDeprecatedClass.php
index 634b6cab3af..be5feffc19e 100644
--- a/tests/phpunit/includes/debug/TestDeprecatedClass.php
+++ b/tests/phpunit/includes/debug/TestDeprecatedClass.php
@@ -23,7 +23,7 @@ class TestDeprecatedClass {
 			}
 		);
 		$this->deprecatePublicPropertyFallback( 'fallbackGetterOnly', '1.25',
-			function () {
+			static function () {
 				return 1;
 			}
 		);
diff --git a/tests/phpunit/includes/deferred/DeferredUpdatesTest.php b/tests/phpunit/includes/deferred/DeferredUpdatesTest.php
index f85a1c455e7..a50a3941e43 100644
--- a/tests/phpunit/includes/deferred/DeferredUpdatesTest.php
+++ b/tests/phpunit/includes/deferred/DeferredUpdatesTest.php
@@ -50,7 +50,7 @@ class DeferredUpdatesTest extends MediaWikiIntegrationTestCase {
 		$this->setMwGlobals( 'wgCommandLineMode', true );
 
 		$ran = 0;
-		DeferredUpdates::addCallableUpdate( function () use ( &$ran ) {
+		DeferredUpdates::addCallableUpdate( static function () use ( &$ran ) {
 			$ran++;
 		} );
 		DeferredUpdates::doUpdates();
@@ -112,43 +112,43 @@ class DeferredUpdatesTest extends MediaWikiIntegrationTestCase {
 			'3-2-1' => "deferred update 1 within deferred update 2 with deferred update 3;\n",
 		];
 		DeferredUpdates::addCallableUpdate(
-			function () use ( $updates ) {
+			static function () use ( $updates ) {
 				echo $updates['1'];
 			}
 		);
 		DeferredUpdates::addCallableUpdate(
-			function () use ( $updates ) {
+			static function () use ( $updates ) {
 				echo $updates['2'];
 				DeferredUpdates::addCallableUpdate(
-					function () use ( $updates ) {
+					static function () use ( $updates ) {
 						echo $updates['2-1'];
 					}
 				);
 				DeferredUpdates::addCallableUpdate(
-					function () use ( $updates ) {
+					static function () use ( $updates ) {
 						echo $updates['2-2'];
 					}
 				);
 			}
 		);
 		DeferredUpdates::addCallableUpdate(
-			function () use ( $updates ) {
+			static function () use ( $updates ) {
 				echo $updates['3'];
 				DeferredUpdates::addCallableUpdate(
-					function () use ( $updates ) {
+					static function () use ( $updates ) {
 						echo $updates['3-1'];
 						DeferredUpdates::addCallableUpdate(
-							function () use ( $updates ) {
+							static function () use ( $updates ) {
 								echo $updates['3-1-1'];
 							}
 						);
 					}
 				);
 				DeferredUpdates::addCallableUpdate(
-					function () use ( $updates ) {
+					static function () use ( $updates ) {
 						echo $updates['3-2'];
 						DeferredUpdates::addCallableUpdate(
-							function () use ( $updates ) {
+							static function () use ( $updates ) {
 								echo $updates['3-2-1'];
 							}
 						);
@@ -166,13 +166,13 @@ class DeferredUpdatesTest extends MediaWikiIntegrationTestCase {
 		$x = null;
 		$y = null;
 		DeferredUpdates::addCallableUpdate(
-			function () use ( &$x ) {
+			static function () use ( &$x ) {
 				$x = 'Sherity';
 			},
 			DeferredUpdates::PRESEND
 		);
 		DeferredUpdates::addCallableUpdate(
-			function () use ( &$y ) {
+			static function () use ( &$y ) {
 				$y = 'Marychu';
 			},
 			DeferredUpdates::POSTSEND
@@ -214,43 +214,43 @@ class DeferredUpdatesTest extends MediaWikiIntegrationTestCase {
 		$lbFactory->commitMasterChanges( __METHOD__ );
 
 		DeferredUpdates::addCallableUpdate(
-			function () use ( $updates ) {
+			static function () use ( $updates ) {
 				echo $updates['1'];
 			}
 		);
 		DeferredUpdates::addCallableUpdate(
-			function () use ( $updates ) {
+			static function () use ( $updates ) {
 				echo $updates['2'];
 				DeferredUpdates::addCallableUpdate(
-					function () use ( $updates ) {
+					static function () use ( $updates ) {
 						echo $updates['2-1'];
 					}
 				);
 				DeferredUpdates::addCallableUpdate(
-					function () use ( $updates ) {
+					static function () use ( $updates ) {
 						echo $updates['2-2'];
 					}
 				);
 			}
 		);
 		DeferredUpdates::addCallableUpdate(
-			function () use ( $updates ) {
+			static function () use ( $updates ) {
 				echo $updates['3'];
 				DeferredUpdates::addCallableUpdate(
-					function () use ( $updates ) {
+					static function () use ( $updates ) {
 						echo $updates['3-1'];
 						DeferredUpdates::addCallableUpdate(
-							function () use ( $updates ) {
+							static function () use ( $updates ) {
 								echo $updates['3-1-1'];
 							}
 						);
 					}
 				);
 				DeferredUpdates::addCallableUpdate(
-					function () use ( $updates ) {
+					static function () use ( $updates ) {
 						echo $updates['3-2'];
 						DeferredUpdates::addCallableUpdate(
-							function () use ( $updates ) {
+							static function () use ( $updates ) {
 								echo $updates['3-2-1'];
 							}
 						);
@@ -280,10 +280,10 @@ class DeferredUpdatesTest extends MediaWikiIntegrationTestCase {
 		$lbFactory->commitMasterChanges( __METHOD__ );
 
 		DeferredUpdates::addCallableUpdate(
-			function () use ( &$x, &$y ) {
+			static function () use ( &$x, &$y ) {
 				$x = true;
 				DeferredUpdates::addCallableUpdate(
-					function () use ( &$y ) {
+					static function () use ( &$y ) {
 						$y = true;
 					},
 					DeferredUpdates::PRESEND
@@ -391,7 +391,7 @@ class DeferredUpdatesTest extends MediaWikiIntegrationTestCase {
 		$called = false;
 		DeferredUpdates::attemptUpdate(
 			new MWCallableUpdate(
-				function () use ( $lbFactory, $fname, &$called ) {
+				static function () use ( $lbFactory, $fname, &$called ) {
 					$lbFactory->flushReplicaSnapshots( $fname );
 					$lbFactory->commitMasterChanges( $fname );
 					$called = true;
@@ -439,7 +439,7 @@ class DeferredUpdatesTest extends MediaWikiIntegrationTestCase {
 					$this->assertSame( 2, DeferredUpdates::getRecursiveExecutionStackDepth() );
 
 					// Add update to subqueue of in-progress top-queue job (not recursive)
-					DeferredUpdates::addCallableUpdate( function () use ( &$resSubSub ) {
+					DeferredUpdates::addCallableUpdate( static function () use ( &$resSubSub ) {
 						$resSubSub = 'b';
 					} );
 
@@ -460,7 +460,7 @@ class DeferredUpdatesTest extends MediaWikiIntegrationTestCase {
 		$this->assertSame( 1, DeferredUpdates::pendingUpdatesCount() );
 		$this->assertSame( 0, DeferredUpdates::getRecursiveExecutionStackDepth() );
 
-		DeferredUpdates::addCallableUpdate( function () use ( &$resA ) {
+		DeferredUpdates::addCallableUpdate( static function () use ( &$resA ) {
 			$resA = 93;
 		} );
 
diff --git a/tests/phpunit/includes/deferred/RefreshSecondaryDataUpdateTest.php b/tests/phpunit/includes/deferred/RefreshSecondaryDataUpdateTest.php
index 2200dde519f..56ae300c8e7 100644
--- a/tests/phpunit/includes/deferred/RefreshSecondaryDataUpdateTest.php
+++ b/tests/phpunit/includes/deferred/RefreshSecondaryDataUpdateTest.php
@@ -22,7 +22,7 @@ class RefreshSecondaryDataUpdateTest extends MediaWikiIntegrationTestCase {
 			->getMock();
 		$goodTrxFname = get_class( $goodUpdate ) . '::doUpdate';
 		$goodUpdate->method( 'doUpdate' )
-			->willReturnCallback( function () use ( &$goodCalls, $lbFactory, $goodTrxFname ) {
+			->willReturnCallback( static function () use ( &$goodCalls, $lbFactory, $goodTrxFname ) {
 				// Update can commit since it owns the transaction
 				$lbFactory->commitMasterChanges( $goodTrxFname );
 				++$goodCalls;
@@ -85,7 +85,7 @@ class RefreshSecondaryDataUpdateTest extends MediaWikiIntegrationTestCase {
 			->getMock();
 		$goodTrxFname = get_class( $goodUpdate ) . '::doUpdate';
 		$goodUpdate->method( 'doUpdate' )
-			->willReturnCallback( function () use ( &$goodCalls, $lbFactory, $goodTrxFname ) {
+			->willReturnCallback( static function () use ( &$goodCalls, $lbFactory, $goodTrxFname ) {
 				// Update can commit since it owns the transaction
 				$lbFactory->commitMasterChanges( $goodTrxFname );
 				++$goodCalls;
@@ -101,7 +101,7 @@ class RefreshSecondaryDataUpdateTest extends MediaWikiIntegrationTestCase {
 		$badUpdate->expects( $this->once() )
 			->method( 'setTransactionTicket' );
 		$badUpdate->method( 'doUpdate' )
-			->willReturnCallback( function () use ( &$badCalls, $lbFactory, $badTrxFname ) {
+			->willReturnCallback( static function () use ( &$badCalls, $lbFactory, $badTrxFname ) {
 				// Update can commit since it owns the transaction
 				$lbFactory->commitMasterChanges( $badTrxFname );
 				++$badCalls;
@@ -190,7 +190,7 @@ class RefreshSecondaryDataUpdateTest extends MediaWikiIntegrationTestCase {
 			->setMethods( [ 'doUpdate' ] )
 			->getMock();
 		$goodUpdate->method( 'doUpdate' )
-			->willReturnCallback( function () use ( &$goodCalls ) {
+			->willReturnCallback( static function () use ( &$goodCalls ) {
 				++$goodCalls;
 			} );
 
@@ -199,7 +199,7 @@ class RefreshSecondaryDataUpdateTest extends MediaWikiIntegrationTestCase {
 			->setMethods( [ 'getSecondaryDataUpdates' ] )
 			->getMock();
 		$updater->method( 'getSecondaryDataUpdates' )
-			->willReturnCallback( function () use ( $dbw, $fname, $goodUpdate ) {
+			->willReturnCallback( static function () use ( $dbw, $fname, $goodUpdate ) {
 				$dbw->selectRow( 'page', '*', '', $fname );
 				$dbw->onTransactionResolution( static function () {
 				}, $fname );
diff --git a/tests/phpunit/includes/diff/UnsupportedSlotDiffRendererTest.php b/tests/phpunit/includes/diff/UnsupportedSlotDiffRendererTest.php
index 9959cb2d865..594d09b0754 100644
--- a/tests/phpunit/includes/diff/UnsupportedSlotDiffRendererTest.php
+++ b/tests/phpunit/includes/diff/UnsupportedSlotDiffRendererTest.php
@@ -31,7 +31,7 @@ class UnsupportedSlotDiffRendererTest extends MediaWikiIntegrationTestCase {
 		$localizer = $this->createMock( MessageLocalizer::class );
 
 		$localizer->method( 'msg' )
-			->willReturnCallback( function ( $key, ...$params ) {
+			->willReturnCallback( static function ( $key, ...$params ) {
 				return new RawMessage( "($key)", $params );
 			} );
 
diff --git a/tests/phpunit/includes/htmlform/HTMLRestrictionsFieldTest.php b/tests/phpunit/includes/htmlform/HTMLRestrictionsFieldTest.php
index bec1df8ffce..d6cbe9ff5ea 100644
--- a/tests/phpunit/includes/htmlform/HTMLRestrictionsFieldTest.php
+++ b/tests/phpunit/includes/htmlform/HTMLRestrictionsFieldTest.php
@@ -36,7 +36,7 @@ class HTMLRestrictionsFieldTest extends PHPUnit\Framework\TestCase {
 		$context = new DerivativeContext( RequestContext::getMain() );
 		$context->setRequest( $request );
 		$form->setContext( $context );
-		$form->setTitle( Title::newFromText( 'Main Page' ) )->setSubmitCallback( function () {
+		$form->setTitle( Title::newFromText( 'Main Page' ) )->setSubmitCallback( static function () {
 			return true;
 		} )->prepareForm();
 		$status = $form->trySubmit();
diff --git a/tests/phpunit/includes/import/ImportTest.php b/tests/phpunit/includes/import/ImportTest.php
index 0d47050c7f1..215192164bb 100644
--- a/tests/phpunit/includes/import/ImportTest.php
+++ b/tests/phpunit/includes/import/ImportTest.php
@@ -85,7 +85,7 @@ EOF
 		$source = new ImportStringSource( $xml );
 
 		$redirect = null;
-		$callback = function ( Title $title, ForeignTitle $foreignTitle, $revCount,
+		$callback = static function ( Title $title, ForeignTitle $foreignTitle, $revCount,
 			$sRevCount, $pageInfo ) use ( &$redirect ) {
 			if ( array_key_exists( 'redirect', $pageInfo ) ) {
 				$redirect = $pageInfo['redirect'];
@@ -171,7 +171,7 @@ EOF
 		$source = new ImportStringSource( $xml );
 
 		$importNamespaces = null;
-		$callback = function ( array $siteinfo, $innerImporter ) use ( &$importNamespaces ) {
+		$callback = static function ( array $siteinfo, $innerImporter ) use ( &$importNamespaces ) {
 			$importNamespaces = $siteinfo['_namespaces'];
 		};
 
diff --git a/tests/phpunit/includes/jobqueue/JobTest.php b/tests/phpunit/includes/jobqueue/JobTest.php
index d827a2c25ba..42b0535831a 100644
--- a/tests/phpunit/includes/jobqueue/JobTest.php
+++ b/tests/phpunit/includes/jobqueue/JobTest.php
@@ -119,7 +119,7 @@ class JobTest extends MediaWikiIntegrationTestCase {
 	public function provideTestJobFactory() {
 		return [
 			'class name' => [ 'NullJob' ],
-			'closure' => [ function ( Title $title, array $params ) {
+			'closure' => [ static function ( Title $title, array $params ) {
 				return Job::factory( 'null', $title, $params );
 			} ],
 			'function' => [ [ $this, 'newNullJob' ] ],
diff --git a/tests/phpunit/includes/libs/GenericArrayObjectTest.php b/tests/phpunit/includes/libs/GenericArrayObjectTest.php
index dba51bea0af..a418a5eb772 100644
--- a/tests/phpunit/includes/libs/GenericArrayObjectTest.php
+++ b/tests/phpunit/includes/libs/GenericArrayObjectTest.php
@@ -164,7 +164,7 @@ abstract class GenericArrayObjectTest extends PHPUnit\Framework\TestCase {
 
 		$this->assertEquals( $listSize, $list->count() );
 
-		$this->checkTypeChecks( function ( GenericArrayObject $list, $element ) {
+		$this->checkTypeChecks( static function ( GenericArrayObject $list, $element ) {
 			$list->append( $element );
 		} );
 	}
@@ -248,7 +248,7 @@ abstract class GenericArrayObjectTest extends PHPUnit\Framework\TestCase {
 
 		$this->assertEquals( count( $elements ), $list->count() );
 
-		$this->checkTypeChecks( function ( GenericArrayObject $list, $element ) {
+		$this->checkTypeChecks( static function ( GenericArrayObject $list, $element ) {
 			$list->offsetSet( mt_rand(), $element );
 		} );
 	}
diff --git a/tests/phpunit/includes/libs/ParamValidator/ParamValidatorTest.php b/tests/phpunit/includes/libs/ParamValidator/ParamValidatorTest.php
index 91edaf3e463..6fb2946fae3 100644
--- a/tests/phpunit/includes/libs/ParamValidator/ParamValidatorTest.php
+++ b/tests/phpunit/includes/libs/ParamValidator/ParamValidatorTest.php
@@ -126,12 +126,12 @@ class ParamValidatorTest extends \PHPUnit\Framework\TestCase {
 			->setConstructorArgs( [ $callbacks ] )
 			->setMethods( [ 'normalizeSettings' ] );
 		$mock1 = $mb->getMockForAbstractClass();
-		$mock1->method( 'normalizeSettings' )->willReturnCallback( function ( $s ) {
+		$mock1->method( 'normalizeSettings' )->willReturnCallback( static function ( $s ) {
 			$s['foo'] = 'FooBar!';
 			return $s;
 		} );
 		$mock2 = $mb->getMockForAbstractClass();
-		$mock2->method( 'normalizeSettings' )->willReturnCallback( function ( $s ) {
+		$mock2->method( 'normalizeSettings' )->willReturnCallback( static function ( $s ) {
 			$s['bar'] = 'FooBar!';
 			return $s;
 		} );
@@ -171,7 +171,7 @@ class ParamValidatorTest extends \PHPUnit\Framework\TestCase {
 			->setMethods( [ 'checkSettings' ] );
 		$mock1 = $mb->getMockForAbstractClass();
 		$mock1->method( 'checkSettings' )->willReturnCallback(
-			function ( string $name, $settings, array $options, array $ret ) {
+			static function ( string $name, $settings, array $options, array $ret ) {
 				$ret['allowedKeys'][] = 'XXX-test';
 				if ( isset( $settings['XXX-test'] ) ) {
 					$ret['issues']['XXX-test'] = 'XXX-test was ' . $settings['XXX-test'];
@@ -181,7 +181,7 @@ class ParamValidatorTest extends \PHPUnit\Framework\TestCase {
 		);
 		$mock2 = $mb->getMockForAbstractClass();
 		$mock2->method( 'checkSettings' )->willReturnCallback(
-			function ( string $name, $settings, array $options, array $ret ) {
+			static function ( string $name, $settings, array $options, array $ret ) {
 				return $ret;
 			}
 		);
diff --git a/tests/phpunit/includes/libs/ParamValidator/Util/UploadedFileStreamTest.php b/tests/phpunit/includes/libs/ParamValidator/Util/UploadedFileStreamTest.php
index c725926f0e8..83885a20a58 100644
--- a/tests/phpunit/includes/libs/ParamValidator/Util/UploadedFileStreamTest.php
+++ b/tests/phpunit/includes/libs/ParamValidator/Util/UploadedFileStreamTest.php
@@ -75,7 +75,7 @@ class UploadedFileStreamTest extends UploadedFileTestBase {
 			->setConstructorArgs( [ $filename ] )
 			->setMethods( [ 'getContents' ] )
 			->getMock();
-		$stream->method( 'getContents' )->willReturnCallback( function () {
+		$stream->method( 'getContents' )->willReturnCallback( static function () {
 			throw new \Error( 'Bogus' );
 		} );
 		$this->assertSame( '', (string)$stream );
diff --git a/tests/phpunit/includes/libs/mime/MimeAnalyzerTest.php b/tests/phpunit/includes/libs/mime/MimeAnalyzerTest.php
index 969f85cf677..f3b9aae3e6b 100644
--- a/tests/phpunit/includes/libs/mime/MimeAnalyzerTest.php
+++ b/tests/phpunit/includes/libs/mime/MimeAnalyzerTest.php
@@ -223,7 +223,7 @@ class MimeAnalyzerTest extends PHPUnit\Framework\TestCase {
 			'infoFile' => MimeAnalyzer::USE_INTERNAL,
 			'typeFile' => MimeAnalyzer::USE_INTERNAL,
 			'xmlTypes' => [],
-			'initCallback' => function ( $instance ) {
+			'initCallback' => static function ( $instance ) {
 				$instance->addExtraTypes( 'fake/mime fake_extension' );
 				$instance->addExtraInfo( 'fake/mime [OFFICE]' );
 				$instance->mExtToMime[ 'no_such_extension' ] = 'fake/mime';
diff --git a/tests/phpunit/includes/libs/objectcache/BagOStuffTestBase.php b/tests/phpunit/includes/libs/objectcache/BagOStuffTestBase.php
index 181f8a743d0..7dc80a06022 100644
--- a/tests/phpunit/includes/libs/objectcache/BagOStuffTestBase.php
+++ b/tests/phpunit/includes/libs/objectcache/BagOStuffTestBase.php
@@ -84,7 +84,7 @@ abstract class BagOStuffTestBase extends MediaWikiIntegrationTestCase {
 
 		$calls = 0;
 		$casRace = false; // emulate a race
-		$callback = function ( BagOStuff $cache, $key, $oldVal, &$expiry ) use ( &$calls, &$casRace ) {
+		$callback = static function ( BagOStuff $cache, $key, $oldVal, &$expiry ) use ( &$calls, &$casRace ) {
 			++$calls;
 			if ( $casRace ) {
 				// Uses CAS instead?
@@ -259,7 +259,7 @@ abstract class BagOStuffTestBase extends MediaWikiIntegrationTestCase {
 		$value = $cache->getWithSetCallback(
 			$key,
 			30,
-			function ( &$ttl ) {
+			static function ( &$ttl ) {
 				$ttl = 10;
 
 				return 'hello kitty';
@@ -387,7 +387,7 @@ abstract class BagOStuffTestBase extends MediaWikiIntegrationTestCase {
 		// 64 * 8 * 32768 = 16777216 bytes
 		$big = str_repeat( wfRandomString( 32 ) . '-' . wfRandomString( 32 ), 32768 );
 
-		$callback = function ( $cache, $key, $oldValue ) {
+		$callback = static function ( $cache, $key, $oldValue ) {
 			return $oldValue . '!';
 		};
 
diff --git a/tests/phpunit/includes/libs/objectcache/MultiWriteBagOStuffTest.php b/tests/phpunit/includes/libs/objectcache/MultiWriteBagOStuffTest.php
index 8eec8bf51cd..1ab27f2e2d6 100644
--- a/tests/phpunit/includes/libs/objectcache/MultiWriteBagOStuffTest.php
+++ b/tests/phpunit/includes/libs/objectcache/MultiWriteBagOStuffTest.php
@@ -58,7 +58,7 @@ class MultiWriteBagOStuffTest extends MediaWikiIntegrationTestCase {
 	public function testSyncMerge() {
 		$key = 'keyA';
 		$value = 'value';
-		$func = function () use ( $value ) {
+		$func = static function () use ( $value ) {
 			return $value;
 		};
 
diff --git a/tests/phpunit/includes/page/ArticleViewTest.php b/tests/phpunit/includes/page/ArticleViewTest.php
index f059ea6ac3d..2d504f8a3fb 100644
--- a/tests/phpunit/includes/page/ArticleViewTest.php
+++ b/tests/phpunit/includes/page/ArticleViewTest.php
@@ -188,7 +188,7 @@ class ArticleViewTest extends MediaWikiIntegrationTestCase {
 
 		$this->setTemporaryHook(
 			'ContentHandlerForModelID',
-			function ( $id, &$handler ) use ( $mockHandler ) {
+			static function ( $id, &$handler ) use ( $mockHandler ) {
 				$handler = $mockHandler;
 			}
 		);
@@ -481,7 +481,7 @@ class ArticleViewTest extends MediaWikiIntegrationTestCase {
 		// use ArticleViewHeader hook to bypass the parser cache
 		$this->setTemporaryHook(
 			'ArticleViewHeader',
-			function ( Article $articlePage, &$outputDone, &$useParserCache ) use ( $article ) {
+			static function ( Article $articlePage, &$outputDone, &$useParserCache ) use ( $article ) {
 				$useParserCache = false;
 			}
 		);
@@ -540,7 +540,7 @@ class ArticleViewTest extends MediaWikiIntegrationTestCase {
 		// use ArticleViewHeader hook to bypass the parser cache
 		$this->setTemporaryHook(
 			'ArticleViewHeader',
-			function ( Article $articlePage, &$outputDone, &$useParserCache ) use ( $article ) {
+			static function ( Article $articlePage, &$outputDone, &$useParserCache ) use ( $article ) {
 				$useParserCache = false;
 			}
 		);
diff --git a/tests/phpunit/includes/page/WikiPageDbTest.php b/tests/phpunit/includes/page/WikiPageDbTest.php
index f207994bf94..80ac20e4ec2 100644
--- a/tests/phpunit/includes/page/WikiPageDbTest.php
+++ b/tests/phpunit/includes/page/WikiPageDbTest.php
@@ -864,7 +864,7 @@ class WikiPageDbTest extends MediaWikiLangTestCase {
 
 		$this->mergeMwGlobalArrayValue(
 			'wgContentHandlers', [
-				$name => function () use ( $handler ){
+				$name => static function () use ( $handler ){
 					return $handler;
 				}
 			]
@@ -2633,7 +2633,7 @@ more stuff
 
 		$this->setTemporaryHook(
 			'WikiPageFactory',
-			function ( $title, &$page ) use ( &$isCalled, $expectedWikiPage ) {
+			static function ( $title, &$page ) use ( &$isCalled, $expectedWikiPage ) {
 				$page = $expectedWikiPage;
 				$isCalled = true;
 
diff --git a/tests/phpunit/includes/parser/ParserCacheSerializationTestCases.php b/tests/phpunit/includes/parser/ParserCacheSerializationTestCases.php
index e845db36eaa..4fe90b31d53 100644
--- a/tests/phpunit/includes/parser/ParserCacheSerializationTestCases.php
+++ b/tests/phpunit/includes/parser/ParserCacheSerializationTestCases.php
@@ -98,13 +98,13 @@ abstract class ParserCacheSerializationTestCases {
 			],
 			'usedOptions' => [
 				'instance' => $cacheTimeWithUsedOptions,
-				'assertions' => function ( MediaWikiIntegrationTestCase $testCase, CacheTime $object ) {
+				'assertions' => static function ( MediaWikiIntegrationTestCase $testCase, CacheTime $object ) {
 					$testCase->assertArrayEquals( [ 'optA', 'optX' ], $object->getUsedOptions() );
 				}
 			],
 			'cacheTime' => [
 				'instance' => $cacheTimeWithTime,
-				'assertions' => function (
+				'assertions' => static function (
 					MediaWikiIntegrationTestCase $testCase, CacheTime $object
 				) use ( $cacheTimestamp ) {
 					$testCase->assertSame( $cacheTimestamp, $object->getCacheTime() );
@@ -112,7 +112,7 @@ abstract class ParserCacheSerializationTestCases {
 			],
 			'cacheExpiry' => [
 				'instance' => $cacheTimeWithExpiry,
-				'assertions' => function (
+				'assertions' => static function (
 					MediaWikiIntegrationTestCase $testCase, CacheTime $object
 				) use ( $cacheExpiry ) {
 					$testCase->assertSame( $cacheExpiry, $object->getCacheExpiry() );
@@ -120,7 +120,7 @@ abstract class ParserCacheSerializationTestCases {
 			],
 			'cacheRevisionId' => [
 				'instance' => $cacheTimeWithRevId,
-				'assertions' => function (
+				'assertions' => static function (
 					MediaWikiIntegrationTestCase $testCase, CacheTime $object
 				) use  ( $cacheRevisionId ) {
 					$testCase->assertSame( $cacheRevisionId, $object->getCacheRevisionId() );
@@ -267,7 +267,7 @@ abstract class ParserCacheSerializationTestCases {
 			],
 			'text' => [
 				'instance' => new ParserOutput( 'Lorem Ipsum' ),
-				'assertions' => function ( MediaWikiIntegrationTestCase $testCase, ParserOutput $object ) {
+				'assertions' => static function ( MediaWikiIntegrationTestCase $testCase, ParserOutput $object ) {
 					$testCase->assertTrue( $object->hasText() );
 					$testCase->assertSame( 'Lorem Ipsum', $object->getRawText() );
 					$testCase->assertSame( 'Lorem Ipsum', $object->getText() );
@@ -275,7 +275,7 @@ abstract class ParserCacheSerializationTestCases {
 			],
 			'usedOptions' => [
 				'instance' => $parserOutputWithUsedOptions,
-				'assertions' => function ( MediaWikiIntegrationTestCase $testCase, ParserOutput $object ) {
+				'assertions' => static function ( MediaWikiIntegrationTestCase $testCase, ParserOutput $object ) {
 					$testCase->assertArrayEquals( [ 'optA', 'optX' ], $object->getUsedOptions() );
 				}
 			],
@@ -370,7 +370,7 @@ abstract class ParserCacheSerializationTestCases {
 			],
 			'withMetadataPost1_31' => [
 				'instance' => $parserOutputWithMetadataPost1_31,
-				'assertions' => function ( MediaWikiIntegrationTestCase $testCase, ParserOutput $object ) {
+				'assertions' => static function ( MediaWikiIntegrationTestCase $testCase, ParserOutput $object ) {
 					$testCase->assertSame( 'test_wrapper', $object->getWrapperDivClass() );
 					$testCase->assertSame( 4242, $object->getSpeculativePageIdUsed() );
 					$testCase->assertSame(
@@ -383,7 +383,7 @@ abstract class ParserCacheSerializationTestCases {
 			],
 			'withMetadataPost1_34' => [
 				'instance' => $parserOutputWithMetadataPost1_34,
-				'assertions' => function ( MediaWikiIntegrationTestCase $testCase, ParserOutput $object ) {
+				'assertions' => static function ( MediaWikiIntegrationTestCase $testCase, ParserOutput $object ) {
 					$testCase->assertArrayEquals( [ 'default1' ], $object->getExtraCSPDefaultSrcs() );
 					$testCase->assertArrayEquals( [ 'script1' ], $object->getExtraCSPScriptSrcs() );
 					$testCase->assertArrayEquals( [ 'style1' ], $object->getExtraCSPStyleSrcs() );
@@ -411,10 +411,10 @@ abstract class ParserCacheSerializationTestCases {
 			$jsonCodec = new JsonCodec();
 			$serializationFormats[] = [
 				'ext' => 'json',
-				'serializer' => function ( JsonSerializable $obj ) use ( $jsonCodec ) {
+				'serializer' => static function ( JsonSerializable $obj ) use ( $jsonCodec ) {
 					return $jsonCodec->serialize( $obj );
 				},
-				'deserializer' => function ( $data ) use ( $jsonCodec ) {
+				'deserializer' => static function ( $data ) use ( $jsonCodec ) {
 					return $jsonCodec->unserialize( $data );
 				}
 			];
diff --git a/tests/phpunit/includes/parser/ParserMethodsTest.php b/tests/phpunit/includes/parser/ParserMethodsTest.php
index 99c21b13bed..937f59afa34 100644
--- a/tests/phpunit/includes/parser/ParserMethodsTest.php
+++ b/tests/phpunit/includes/parser/ParserMethodsTest.php
@@ -242,7 +242,7 @@ class ParserMethodsTest extends MediaWikiLangTestCase {
 		$oldRevision->setContent( SlotRecord::MAIN, new WikitextContent( 'FAUX' ) );
 
 		$po = new ParserOptions( $frank );
-		$po->setCurrentRevisionRecordCallback( function () use ( $oldRevision ) {
+		$po->setCurrentRevisionRecordCallback( static function () use ( $oldRevision ) {
 			return $oldRevision;
 		} );
 
@@ -271,7 +271,7 @@ class ParserMethodsTest extends MediaWikiLangTestCase {
 
 		$po = new ParserOptions( $frank );
 		$po->setIsPreview( true );
-		$po->setCurrentRevisionRecordCallback( function () use ( $newRevision ) {
+		$po->setCurrentRevisionRecordCallback( static function () use ( $newRevision ) {
 			return $newRevision;
 		} );
 
@@ -284,7 +284,7 @@ class ParserMethodsTest extends MediaWikiLangTestCase {
 		];
 
 		$po = new ParserOptions( $frank );
-		$po->setCurrentRevisionRecordCallback( function () use ( $newRevision ) {
+		$po->setCurrentRevisionRecordCallback( static function () use ( $newRevision ) {
 			return $newRevision;
 		} );
 
@@ -306,7 +306,7 @@ class ParserMethodsTest extends MediaWikiLangTestCase {
 
 		$po = new ParserOptions( $frank );
 		$po->setIsPreview( true );
-		$po->setCurrentRevisionRecordCallback( function () use ( $newRevision ) {
+		$po->setCurrentRevisionRecordCallback( static function () use ( $newRevision ) {
 			return $newRevision;
 		} );
 
diff --git a/tests/phpunit/includes/parser/ParserOptionsTest.php b/tests/phpunit/includes/parser/ParserOptionsTest.php
index afed46241b2..8dd2256c007 100644
--- a/tests/phpunit/includes/parser/ParserOptionsTest.php
+++ b/tests/phpunit/includes/parser/ParserOptionsTest.php
@@ -282,7 +282,7 @@ class ParserOptionsTest extends MediaWikiLangTestCase {
 		$classWrapper = TestingAccessWrapper::newFromClass( ParserOptions::class );
 		$oldDefaults = $classWrapper->defaults;
 		$oldLazy = $classWrapper->lazyOptions;
-		$reset = new ScopedCallback( function () use ( $classWrapper, $oldDefaults, $oldLazy ) {
+		$reset = new ScopedCallback( static function () use ( $classWrapper, $oldDefaults, $oldLazy ) {
 			$classWrapper->defaults = $oldDefaults;
 			$classWrapper->lazyOptions = $oldLazy;
 		} );
@@ -300,7 +300,7 @@ class ParserOptionsTest extends MediaWikiLangTestCase {
 
 		$ctr = 0;
 		$classWrapper->defaults += [ __METHOD__ => null ];
-		$classWrapper->lazyOptions += [ __METHOD__ => function () use ( &$ctr ) {
+		$classWrapper->lazyOptions += [ __METHOD__ => static function () use ( &$ctr ) {
 			return ++$ctr;
 		} ];
 		$popt1 = ParserOptions::newCanonical( 'canonical' );
@@ -346,7 +346,7 @@ class ParserOptionsTest extends MediaWikiLangTestCase {
 
 		self::clearCache();
 
-		$this->setTemporaryHook( 'ParserOptionsRegister', function ( &$defaults, &$inCacheKey ) {
+		$this->setTemporaryHook( 'ParserOptionsRegister', static function ( &$defaults, &$inCacheKey ) {
 			$defaults += [
 				'foo' => 'foo',
 				'bar' => 'bar',
@@ -369,7 +369,7 @@ class ParserOptionsTest extends MediaWikiLangTestCase {
 		$this->assertFalse( $options->getSpeculativeRevId() );
 
 		$counter = 0;
-		$options->setSpeculativeRevIdCallback( function () use( &$counter ) {
+		$options->setSpeculativeRevIdCallback( static function () use( &$counter ) {
 			return ++$counter;
 		} );
 
diff --git a/tests/phpunit/includes/parser/ParserOutputTest.php b/tests/phpunit/includes/parser/ParserOutputTest.php
index abf952e73a1..207304f5e58 100644
--- a/tests/phpunit/includes/parser/ParserOutputTest.php
+++ b/tests/phpunit/includes/parser/ParserOutputTest.php
@@ -984,7 +984,7 @@ EOF
 	 */
 	public function testGetCacheTime() {
 		$clock = MWTimestamp::convert( TS_UNIX, '20100101000000' );
-		MWTimestamp::setFakeTime( function () use ( &$clock ) {
+		MWTimestamp::setFakeTime( static function () use ( &$clock ) {
 			return $clock++;
 		} );
 
diff --git a/tests/phpunit/includes/poolcounter/PoolWorkArticleViewTest.php b/tests/phpunit/includes/poolcounter/PoolWorkArticleViewTest.php
index 246f9e63813..77b0ba3917c 100644
--- a/tests/phpunit/includes/poolcounter/PoolWorkArticleViewTest.php
+++ b/tests/phpunit/includes/poolcounter/PoolWorkArticleViewTest.php
@@ -117,25 +117,25 @@ class PoolWorkArticleViewTest extends MediaWikiIntegrationTestCase {
 	public function provideMagicWords() {
 		yield 'PAGEID' => [
 			'Test {{PAGEID}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return $rev->getPageId();
 			}
 		];
 		yield 'REVISIONID' => [
 			'Test {{REVISIONID}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return $rev->getId();
 			}
 		];
 		yield 'REVISIONUSER' => [
 			'Test {{REVISIONUSER}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return $rev->getUser()->getName();
 			}
 		];
 		yield 'REVISIONTIMESTAMP' => [
 			'Test {{REVISIONTIMESTAMP}} Test',
-			function ( RevisionRecord $rev ) {
+			static function ( RevisionRecord $rev ) {
 				return $rev->getTimestamp();
 			}
 		];
diff --git a/tests/phpunit/includes/resourceloader/DerivativeResourceLoaderContextTest.php b/tests/phpunit/includes/resourceloader/DerivativeResourceLoaderContextTest.php
index 17f5bdfcf5d..9adcc2939ff 100644
--- a/tests/phpunit/includes/resourceloader/DerivativeResourceLoaderContextTest.php
+++ b/tests/phpunit/includes/resourceloader/DerivativeResourceLoaderContextTest.php
@@ -130,7 +130,7 @@ class DerivativeResourceLoaderContextTest extends MediaWikiIntegrationTestCase {
 		$derived = new DerivativeResourceLoaderContext( self::makeContext() );
 		$this->assertNull( $derived->getContentOverrideCallback(), 'default' );
 
-		$override = function ( Title $t ) {
+		$override = static function ( Title $t ) {
 			return null;
 		};
 		$derived->setContentOverrideCallback( $override );
diff --git a/tests/phpunit/includes/resourceloader/ResourceLoaderFileModuleTest.php b/tests/phpunit/includes/resourceloader/ResourceLoaderFileModuleTest.php
index b5659e88632..de21e40591a 100644
--- a/tests/phpunit/includes/resourceloader/ResourceLoaderFileModuleTest.php
+++ b/tests/phpunit/includes/resourceloader/ResourceLoaderFileModuleTest.php
@@ -455,40 +455,40 @@ class ResourceLoaderFileModuleTest extends ResourceLoaderTestCase {
 		yield 'identical Less variables' => [ $x, $x, true ];
 
 		$a = [
-			'packageFiles' => [ [ 'name' => 'data.json', 'callback' => function () {
+			'packageFiles' => [ [ 'name' => 'data.json', 'callback' => static function () {
 				return [ 'aaa' ];
 			} ] ]
 		];
 		$b = [
-			'packageFiles' => [ [ 'name' => 'data.json', 'callback' => function () {
+			'packageFiles' => [ [ 'name' => 'data.json', 'callback' => static function () {
 				return [ 'bbb' ];
 			} ] ]
 		];
 		yield 'packageFiles with different callback' => [ $a, $b, false ];
 
 		$a = [
-			'packageFiles' => [ [ 'name' => 'aaa.json', 'callback' => function () {
+			'packageFiles' => [ [ 'name' => 'aaa.json', 'callback' => static function () {
 				return [ 'x' ];
 			} ] ]
 		];
 		$b = [
-			'packageFiles' => [ [ 'name' => 'bbb.json', 'callback' => function () {
+			'packageFiles' => [ [ 'name' => 'bbb.json', 'callback' => static function () {
 				return [ 'x' ];
 			} ] ]
 		];
 		yield 'packageFiles with different file name and a callback' => [ $a, $b, false ];
 
 		$a = [
-			'packageFiles' => [ [ 'name' => 'data.json', 'versionCallback' => function () {
+			'packageFiles' => [ [ 'name' => 'data.json', 'versionCallback' => static function () {
 				return [ 'A-version' ];
-			}, 'callback' => function () {
+			}, 'callback' => static function () {
 				throw new Exception( 'Unexpected computation' );
 			} ] ]
 		];
 		$b = [
-			'packageFiles' => [ [ 'name' => 'data.json', 'versionCallback' => function () {
+			'packageFiles' => [ [ 'name' => 'data.json', 'versionCallback' => static function () {
 				return [ 'B-version' ];
-			}, 'callback' => function () {
+			}, 'callback' => static function () {
 				throw new Exception( 'Unexpected computation' );
 			} ] ]
 		];
@@ -496,20 +496,20 @@ class ResourceLoaderFileModuleTest extends ResourceLoaderTestCase {
 
 		$a = [
 			'packageFiles' => [ [ 'name' => 'aaa.json',
-				'versionCallback' => function () {
+				'versionCallback' => static function () {
 					return [ 'X-version' ];
 				},
-				'callback' => function () {
+				'callback' => static function () {
 					throw new Exception( 'Unexpected computation' );
 				}
 			] ]
 		];
 		$b = [
 			'packageFiles' => [ [ 'name' => 'bbb.json',
-				'versionCallback' => function () {
+				'versionCallback' => static function () {
 					return [ 'X-version' ];
 				},
-				'callback' => function () {
+				'callback' => static function () {
 					throw new Exception( 'Unexpected computation' );
 				}
 			] ]
@@ -623,7 +623,7 @@ class ResourceLoaderFileModuleTest extends ResourceLoaderTestCase {
 						[ 'name' => 'bar.js', 'content' => "console.log('Hello');" ],
 						[
 							'name' => 'data.json',
-							'callback' => function ( $context, $config, $extra ) {
+							'callback' => static function ( $context, $config, $extra ) {
 								return [ 'langCode' => $context->getLanguage(), 'extra' => $extra ];
 							},
 							'callbackParam' => [ 'a' => 'b' ],
@@ -672,10 +672,10 @@ class ResourceLoaderFileModuleTest extends ResourceLoaderTestCase {
 						[ 'name' => 'bar.js', 'content' => "console.log('Hello');" ],
 						[
 							'name' => 'data.json',
-							'versionCallback' => function ( $context ) {
+							'versionCallback' => static function ( $context ) {
 								return 'x';
 							},
-							'callback' => function ( $context, $config, $extra ) {
+							'callback' => static function ( $context, $config, $extra ) {
 								return [ 'langCode' => $context->getLanguage(), 'extra' => $extra ];
 							},
 							'callbackParam' => [ 'A', 'B' ]
@@ -702,7 +702,7 @@ class ResourceLoaderFileModuleTest extends ResourceLoaderTestCase {
 			'package file with callback that returns a file (1)' => [
 				$base + [
 					'packageFiles' => [
-						[ 'name' => 'dynamic.js', 'callback' => function ( $context ) {
+						[ 'name' => 'dynamic.js', 'callback' => static function ( $context ) {
 							$file = $context->getLanguage() === 'fy' ? 'script-comment.js' : 'script-nosemi.js';
 							return new ResourceLoaderFilePath( $file );
 						} ]
@@ -724,7 +724,7 @@ class ResourceLoaderFileModuleTest extends ResourceLoaderTestCase {
 			'package file with callback that returns a file (2)' => [
 				$base + [
 					'packageFiles' => [
-						[ 'name' => 'dynamic.js', 'callback' => function ( $context ) {
+						[ 'name' => 'dynamic.js', 'callback' => static function ( $context ) {
 							$file = $context->getLanguage() === 'fy' ? 'script-comment.js' : 'script-nosemi.js';
 							return new ResourceLoaderFilePath( $file );
 						} ]
diff --git a/tests/phpunit/includes/resourceloader/ResourceLoaderTest.php b/tests/phpunit/includes/resourceloader/ResourceLoaderTest.php
index 891ee424e84..26a211f93f7 100644
--- a/tests/phpunit/includes/resourceloader/ResourceLoaderTest.php
+++ b/tests/phpunit/includes/resourceloader/ResourceLoaderTest.php
@@ -22,7 +22,7 @@ class ResourceLoaderTest extends ResourceLoaderTestCase {
 		$ranHook = 0;
 		$this->setMwGlobals( 'wgHooks', [
 			'ResourceLoaderRegisterModules' => [
-				function ( &$resourceLoader ) use ( &$ranHook ) {
+				static function ( &$resourceLoader ) use ( &$ranHook ) {
 					$ranHook++;
 				}
 			]
@@ -155,14 +155,14 @@ class ResourceLoaderTest extends ResourceLoaderTestCase {
 		return [
 			'factory ignored' => [ false,
 				[
-					'factory' => function () {
+					'factory' => static function () {
 						return new ResourceLoaderTestModule();
 					}
 				]
 			],
 			'factory ignored (actual FileModule)' => [ false,
 				[
-					'factory' => function () use ( $fileModuleObj ) {
+					'factory' => static function () use ( $fileModuleObj ) {
 						return $fileModuleObj;
 					}
 				]
@@ -1125,7 +1125,7 @@ END
 			] )
 			->getMock();
 		$rl->register( 'test', [
-			'factory' => function () use ( $module ) {
+			'factory' => static function () use ( $module ) {
 				return $module;
 			}
 		] );
@@ -1184,7 +1184,7 @@ END
 			] )
 			->getMock();
 		$rl->register( 'test', [
-			'factory' => function () use ( $module ) {
+			'factory' => static function () use ( $module ) {
 				return $module;
 			}
 		] );
diff --git a/tests/phpunit/includes/resourceloader/ResourceLoaderWikiModuleTest.php b/tests/phpunit/includes/resourceloader/ResourceLoaderWikiModuleTest.php
index 19f6201ad54..60d6f9ff5f4 100644
--- a/tests/phpunit/includes/resourceloader/ResourceLoaderWikiModuleTest.php
+++ b/tests/phpunit/includes/resourceloader/ResourceLoaderWikiModuleTest.php
@@ -382,7 +382,7 @@ class ResourceLoaderWikiModuleTest extends ResourceLoaderTestCase {
 		$context = new DerivativeResourceLoaderContext(
 			new ResourceLoaderContext( $rl, new FauxRequest() )
 		);
-		$context->setContentOverrideCallback( function ( Title $t ) {
+		$context->setContentOverrideCallback( static function ( Title $t ) {
 			if ( $t->getPrefixedText() === 'MediaWiki:Common.css' ) {
 				return new CssContent( '.override{}' );
 			}
@@ -396,7 +396,7 @@ class ResourceLoaderWikiModuleTest extends ResourceLoaderTestCase {
 			]
 		], $module->getStyles( $context ) );
 
-		$context->setContentOverrideCallback( function ( Title $t ) {
+		$context->setContentOverrideCallback( static function ( Title $t ) {
 			if ( $t->getPrefixedText() === 'MediaWiki:Skin.css' ) {
 				return new CssContent( '.override{}' );
 			}
@@ -417,7 +417,7 @@ class ResourceLoaderWikiModuleTest extends ResourceLoaderTestCase {
 			->willReturn( [
 				'MediaWiki:Redirect.js' => [ 'type' => 'script' ]
 			] );
-		$context->setContentOverrideCallback( function ( Title $title ) {
+		$context->setContentOverrideCallback( static function ( Title $title ) {
 			if ( $title->getPrefixedText() === 'MediaWiki:Redirect.js' ) {
 				$handler = new JavaScriptContentHandler();
 				return $handler->makeRedirectContent(
diff --git a/tests/phpunit/includes/search/SearchEnginePrefixTest.php b/tests/phpunit/includes/search/SearchEnginePrefixTest.php
index 8d8b551ebb4..3ecbccfa4e7 100644
--- a/tests/phpunit/includes/search/SearchEnginePrefixTest.php
+++ b/tests/phpunit/includes/search/SearchEnginePrefixTest.php
@@ -70,7 +70,7 @@ class SearchEnginePrefixTest extends MediaWikiLangTestCase {
 		} else {
 			$this->setMwGlobals( 'wgHooks', [
 				'PrefixSearchBackend' => [
-					function ( $namespaces, $search, $limit, &$srchres ) use ( $results ) {
+					static function ( $namespaces, $search, $limit, &$srchres ) use ( $results ) {
 						$srchres = $results;
 						return false;
 					}
@@ -340,7 +340,7 @@ class SearchEnginePrefixTest extends MediaWikiLangTestCase {
 		$search = $this->mockSearchWithResults( $case['provision'] );
 		$results = $search->completionSearch( $case['query'] );
 
-		$results = $results->map( function ( SearchSuggestion $s ) {
+		$results = $results->map( static function ( SearchSuggestion $s ) {
 			return $s->getText();
 		} );
 
diff --git a/tests/phpunit/includes/search/SearchEngineTest.php b/tests/phpunit/includes/search/SearchEngineTest.php
index 7ee1674f339..9b275b329ee 100644
--- a/tests/phpunit/includes/search/SearchEngineTest.php
+++ b/tests/phpunit/includes/search/SearchEngineTest.php
@@ -312,7 +312,7 @@ class SearchEngineTest extends MediaWikiLangTestCase {
 
 		// Not using mock since PHPUnit mocks do not work properly with references in params
 		$this->setTemporaryHook( 'SearchIndexFields',
-			function ( &$fields, SearchEngine $engine ) use ( $mockFieldBuilder ) {
+			static function ( &$fields, SearchEngine $engine ) use ( $mockFieldBuilder ) {
 				$fields['testField'] =
 					$mockFieldBuilder( "testField", SearchIndexField::INDEX_TYPE_TEXT );
 				return true;
@@ -354,7 +354,7 @@ class SearchEngineTest extends MediaWikiLangTestCase {
 		$setAugmentor = $this->createMock( ResultSetAugmentor::class );
 		$setAugmentor->expects( $this->once() )
 			->method( 'augmentAll' )
-			->willReturnCallback( function ( ISearchResultSet $resultSet ) {
+			->willReturnCallback( static function ( ISearchResultSet $resultSet ) {
 				$data = [];
 				/** @var SearchResult $result */
 				foreach ( $resultSet as $result ) {
@@ -368,7 +368,7 @@ class SearchEngineTest extends MediaWikiLangTestCase {
 		$rowAugmentor = $this->createMock( ResultAugmentor::class );
 		$rowAugmentor->expects( $this->exactly( 2 ) )
 			->method( 'augment' )
-			->willReturnCallback( function ( SearchResult $result ) {
+			->willReturnCallback( static function ( SearchResult $result ) {
 				$id = $result->getTitle()->getArticleID();
 				return "Result2:$id:" . $result->getTitle()->getText();
 			} );
@@ -491,7 +491,7 @@ class SearchEngineTest extends MediaWikiLangTestCase {
 	 * @dataProvider provideDataForParseNamespacePrefix
 	 */
 	public function testParseNamespacePrefix( array $params, $expected ) {
-		$this->setTemporaryHook( 'PrefixSearchExtractNamespace', function ( &$namespaces, &$query ) {
+		$this->setTemporaryHook( 'PrefixSearchExtractNamespace', static function ( &$namespaces, &$query ) {
 			if ( strpos( $query, 'hélp:' ) === 0 ) {
 				$namespaces = [ NS_HELP ];
 				$query = substr( $query, strlen( 'hélp:' ) );
diff --git a/tests/phpunit/includes/search/SearchNearMatcherTest.php b/tests/phpunit/includes/search/SearchNearMatcherTest.php
index e75fa7438d5..0825b286748 100644
--- a/tests/phpunit/includes/search/SearchNearMatcherTest.php
+++ b/tests/phpunit/includes/search/SearchNearMatcherTest.php
@@ -104,7 +104,7 @@ class SearchNearMatcherTest extends MediaWikiIntegrationTestCase {
 			'EnableSearchContributorsByIP' => false,
 		] );
 
-		$this->setTemporaryHook( $hook, function ( $term, &$title ) {
+		$this->setTemporaryHook( $hook, static function ( $term, &$title ) {
 			if ( $term === [ 'Hook' ] || $term === 'Hook' ) {
 				$title = Title::newFromText( 'TitleFromHook' );
 				return false;
diff --git a/tests/phpunit/includes/search/SearchResultTraitTest.php b/tests/phpunit/includes/search/SearchResultTraitTest.php
index acba7b87486..f870542025e 100644
--- a/tests/phpunit/includes/search/SearchResultTraitTest.php
+++ b/tests/phpunit/includes/search/SearchResultTraitTest.php
@@ -12,7 +12,7 @@ class SearchResultTraitTest extends MediaWikiIntegrationTestCase {
 		$this->assertEquals( [], $result->getExtensionData(), 'starts empty' );
 
 		$data = [ 'hello' => 'world' ];
-		$result->setExtensionData( function () use ( &$data ) {
+		$result->setExtensionData( static function () use ( &$data ) {
 			return $data;
 		} );
 		$this->assertEquals( $data, $result->getExtensionData(), 'can set extension data' );
diff --git a/tests/phpunit/includes/session/PHPSessionHandlerTest.php b/tests/phpunit/includes/session/PHPSessionHandlerTest.php
index a5b1b8a13eb..0af4f9878ab 100644
--- a/tests/phpunit/includes/session/PHPSessionHandlerTest.php
+++ b/tests/phpunit/includes/session/PHPSessionHandlerTest.php
@@ -74,7 +74,7 @@ class PHPSessionHandlerTest extends MediaWikiIntegrationTestCase {
 
 		$store = new TestBagOStuff();
 		// Tolerate debug message, anything else is unexpected
-		$logger = new \TestLogger( false, function ( $m ) {
+		$logger = new \TestLogger( false, static function ( $m ) {
 			return preg_match( '/^SessionManager using store/', $m ) ? null : $m;
 		} );
 		$manager = new SessionManager( [
@@ -110,7 +110,7 @@ class PHPSessionHandlerTest extends MediaWikiIntegrationTestCase {
 		] );
 
 		$store = new TestBagOStuff();
-		$logger = new \TestLogger( true, function ( $m ) {
+		$logger = new \TestLogger( true, static function ( $m ) {
 			return (
 				// Discard all log events starting with expected prefix
 				preg_match( '/^SessionBackend "\{session\}" /', $m )
@@ -291,7 +291,7 @@ class PHPSessionHandlerTest extends MediaWikiIntegrationTestCase {
 		session_id( $id );
 		session_start();
 		$this->mergeMwGlobalArrayValue( 'wgHooks', [
-			'SessionCheckInfo' => [ function ( &$reason ) {
+			'SessionCheckInfo' => [ static function ( &$reason ) {
 				$reason = 'Testing';
 				return false;
 			} ],
diff --git a/tests/phpunit/includes/session/SessionBackendTest.php b/tests/phpunit/includes/session/SessionBackendTest.php
index 962b9fee601..9d526c98c65 100644
--- a/tests/phpunit/includes/session/SessionBackendTest.php
+++ b/tests/phpunit/includes/session/SessionBackendTest.php
@@ -729,7 +729,7 @@ class SessionBackendTest extends MediaWikiIntegrationTestCase {
 			->setMethods( [ 'onSessionMetadata' ] )->getMock();
 		$mockHook->expects( $this->any() )->method( 'onSessionMetadata' )
 			->will( $this->returnCallback(
-				function ( SessionBackend $backend, array &$metadata, array $requests ) {
+				static function ( SessionBackend $backend, array &$metadata, array $requests ) {
 					$metadata['userId']++;
 				}
 			) );
@@ -857,7 +857,7 @@ class SessionBackendTest extends MediaWikiIntegrationTestCase {
 			$rProp = new \ReflectionProperty( PHPSessionHandler::class, 'instance' );
 			$rProp->setAccessible( true );
 			$handler = TestingAccessWrapper::newFromObject( $rProp->getValue() );
-			$resetHandler = new \Wikimedia\ScopedCallback( function () use ( $handler ) {
+			$resetHandler = new \Wikimedia\ScopedCallback( static function () use ( $handler ) {
 				session_write_close();
 				$handler->enable = false;
 			} );
@@ -897,7 +897,7 @@ class SessionBackendTest extends MediaWikiIntegrationTestCase {
 			$rProp = new \ReflectionProperty( PHPSessionHandler::class, 'instance' );
 			$rProp->setAccessible( true );
 			$handler = TestingAccessWrapper::newFromObject( $rProp->getValue() );
-			$resetHandler = new \Wikimedia\ScopedCallback( function () use ( $handler ) {
+			$resetHandler = new \Wikimedia\ScopedCallback( static function () use ( $handler ) {
 				session_write_close();
 				$handler->enable = false;
 			} );
@@ -933,7 +933,7 @@ class SessionBackendTest extends MediaWikiIntegrationTestCase {
 			$rProp = new \ReflectionProperty( PHPSessionHandler::class, 'instance' );
 			$rProp->setAccessible( true );
 			$handler = TestingAccessWrapper::newFromObject( $rProp->getValue() );
-			$resetHandler = new \Wikimedia\ScopedCallback( function () use ( $handler ) {
+			$resetHandler = new \Wikimedia\ScopedCallback( static function () use ( $handler ) {
 				session_write_close();
 				$handler->enable = false;
 			} );
diff --git a/tests/phpunit/includes/session/SessionManagerTest.php b/tests/phpunit/includes/session/SessionManagerTest.php
index 95a679938f4..2d5625e953b 100644
--- a/tests/phpunit/includes/session/SessionManagerTest.php
+++ b/tests/phpunit/includes/session/SessionManagerTest.php
@@ -34,7 +34,7 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 				[ 'class' => \DummySessionProvider::class ],
 			]
 		] );
-		$this->logger = new \TestLogger( false, function ( $m ) {
+		$this->logger = new \TestLogger( false, static function ( $m ) {
 			return ( strpos( $m, 'SessionBackend ' ) === 0
 				|| strpos( $m, 'SessionManager using store ' ) === 0
 				// These were added for T264793 and behave somewhat erratically, not worth testing
@@ -52,7 +52,7 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 	}
 
 	protected function objectCacheDef( $object ) {
-		return [ 'factory' => function () use ( $object ) {
+		return [ 'factory' => static function () use ( $object ) {
 			return $object;
 		} ];
 	}
@@ -75,7 +75,7 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 		$rProp->setAccessible( true );
 		$handler = TestingAccessWrapper::newFromObject( $rProp->getValue() );
 		$oldEnable = $handler->enable;
-		$reset[] = new \Wikimedia\ScopedCallback( function () use ( $handler, $oldEnable ) {
+		$reset[] = new \Wikimedia\ScopedCallback( static function () use ( $handler, $oldEnable ) {
 			if ( $handler->enable ) {
 				session_write_close();
 			}
@@ -160,11 +160,11 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 		$provider1 = $providerBuilder->getMock();
 		$provider1->expects( $this->any() )->method( 'provideSessionInfo' )
 			->with( $this->identicalTo( $request ) )
-			->will( $this->returnCallback( function ( $request ) {
+			->will( $this->returnCallback( static function ( $request ) {
 				return $request->info1;
 			} ) );
 		$provider1->expects( $this->any() )->method( 'newSessionInfo' )
-			->will( $this->returnCallback( function () use ( $idEmpty, $provider1 ) {
+			->will( $this->returnCallback( static function () use ( $idEmpty, $provider1 ) {
 				return new SessionInfo( SessionInfo::MIN_PRIORITY, [
 					'provider' => $provider1,
 					'id' => $idEmpty,
@@ -177,14 +177,14 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 		$provider1->expects( $this->any() )->method( 'describe' )
 			->will( $this->returnValue( '#1 sessions' ) );
 		$provider1->expects( $this->any() )->method( 'unpersistSession' )
-			->will( $this->returnCallback( function ( $request ) {
+			->will( $this->returnCallback( static function ( $request ) {
 				$request->unpersist1 = true;
 			} ) );
 
 		$provider2 = $providerBuilder->getMock();
 		$provider2->expects( $this->any() )->method( 'provideSessionInfo' )
 			->with( $this->identicalTo( $request ) )
-			->will( $this->returnCallback( function ( $request ) {
+			->will( $this->returnCallback( static function ( $request ) {
 				return $request->info2;
 			} ) );
 		$provider2->expects( $this->any() )->method( '__toString' )
@@ -192,7 +192,7 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 		$provider2->expects( $this->any() )->method( 'describe' )
 			->will( $this->returnValue( '#2 sessions' ) );
 		$provider2->expects( $this->any() )->method( 'unpersistSession' )
-			->will( $this->returnCallback( function ( $request ) {
+			->will( $this->returnCallback( static function ( $request ) {
 				$request->unpersist2 = true;
 			} ) );
 
@@ -447,10 +447,10 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 		$provider1->expects( $this->any() )->method( 'provideSessionInfo' )
 			->will( $this->returnValue( null ) );
 		$provider1->expects( $this->any() )->method( 'newSessionInfo' )
-			->with( $this->callback( function ( $id ) use ( &$expectId ) {
+			->with( $this->callback( static function ( $id ) use ( &$expectId ) {
 				return $id === $expectId;
 			} ) )
-			->will( $this->returnCallback( function () use ( &$info1 ) {
+			->will( $this->returnCallback( static function () use ( &$info1 ) {
 				return $info1;
 			} ) );
 		$provider1->expects( $this->any() )->method( '__toString' )
@@ -460,10 +460,10 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 		$provider2->expects( $this->any() )->method( 'provideSessionInfo' )
 			->will( $this->returnValue( null ) );
 		$provider2->expects( $this->any() )->method( 'newSessionInfo' )
-			->with( $this->callback( function ( $id ) use ( &$expectId ) {
+			->with( $this->callback( static function ( $id ) use ( &$expectId ) {
 				return $id === $expectId;
 			} ) )
-			->will( $this->returnCallback( function () use ( &$info2 ) {
+			->will( $this->returnCallback( static function () use ( &$info2 ) {
 				return $info2;
 			} ) );
 		$provider1->expects( $this->any() )->method( '__toString' )
@@ -942,7 +942,7 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 		$provider->expects( $this->any() )->method( '__toString' )
 			->will( $this->returnValue( 'Mock' ) );
 		$provider->expects( $this->any() )->method( 'mergeMetadata' )
-			->will( $this->returnCallback( function ( $a, $b ) {
+			->will( $this->returnCallback( static function ( $a, $b ) {
 				if ( $b === [ 'Throw' ] ) {
 					throw new MetadataMergeException( 'no merge!' );
 				}
@@ -958,7 +958,7 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 		$provider2->expects( $this->any() )->method( '__toString' )
 			->will( $this->returnValue( 'Mock2' ) );
 		$provider2->expects( $this->any() )->method( 'refreshSessionInfo' )
-			->will( $this->returnCallback( function ( $info, $request, &$metadata ) {
+			->will( $this->returnCallback( static function ( $info, $request, &$metadata ) {
 				$metadata['changed'] = true;
 				return true;
 			} ) );
@@ -1541,7 +1541,7 @@ class SessionManagerTest extends MediaWikiIntegrationTestCase {
 		$request->setCookie( 'mwuser-sessionId', $mwuser );
 
 		$proxyLookup = $this->createMock( \ProxyLookup::class );
-		$proxyLookup->method( 'isConfiguredProxy' )->willReturnCallback( function ( $ip ) {
+		$proxyLookup->method( 'isConfiguredProxy' )->willReturnCallback( static function ( $ip ) {
 			return $ip === '11.22.33.44';
 		} );
 		$this->setService( 'ProxyLookup', $proxyLookup );
diff --git a/tests/phpunit/includes/session/SessionTest.php b/tests/phpunit/includes/session/SessionTest.php
index fdb12e4533d..8ccca4e12ab 100644
--- a/tests/phpunit/includes/session/SessionTest.php
+++ b/tests/phpunit/includes/session/SessionTest.php
@@ -23,7 +23,7 @@ class SessionTest extends MediaWikiIntegrationTestCase {
 		$backend->expects( $this->once() )->method( 'canSetUser' )
 			->will( $this->returnValue( true ) );
 		$backend->expects( $this->once() )->method( 'setUser' )
-			->with( $this->callback( function ( $user ) {
+			->with( $this->callback( static function ( $user ) {
 				return $user instanceof User && $user->isAnon();
 			} ) );
 		$backend->expects( $this->once() )->method( 'save' );
@@ -39,7 +39,7 @@ class SessionTest extends MediaWikiIntegrationTestCase {
 		$backend->expects( $this->once() )->method( 'canSetUser' )
 			->will( $this->returnValue( true ) );
 		$backend->expects( $this->once() )->method( 'setUser' )
-			->with( $this->callback( function ( $user ) {
+			->with( $this->callback( static function ( $user ) {
 				return $user instanceof User && $user->isAnon();
 			} ) );
 		$backend->expects( $this->once() )->method( 'save' );
diff --git a/tests/phpunit/includes/session/TestUtils.php b/tests/phpunit/includes/session/TestUtils.php
index 4499c31157f..ac4d87b5483 100644
--- a/tests/phpunit/includes/session/TestUtils.php
+++ b/tests/phpunit/includes/session/TestUtils.php
@@ -47,7 +47,7 @@ class TestUtils {
 			PHPSessionHandler::install( $manager );
 		}
 
-		return new \Wikimedia\ScopedCallback( function () use ( &$reset, $oldInstance ) {
+		return new \Wikimedia\ScopedCallback( static function () use ( &$reset, $oldInstance ) {
 			foreach ( $reset as &$arr ) {
 				$arr[0]->setValue( $arr[1] );
 			}
diff --git a/tests/phpunit/includes/shell/CommandTest.php b/tests/phpunit/includes/shell/CommandTest.php
index c5335522864..b759cfd0928 100644
--- a/tests/phpunit/includes/shell/CommandTest.php
+++ b/tests/phpunit/includes/shell/CommandTest.php
@@ -141,7 +141,7 @@ class CommandTest extends PHPUnit\Framework\TestCase {
 	}
 
 	public function testLogStderr() {
-		$logger = new TestLogger( true, function ( $message, $level, $context ) {
+		$logger = new TestLogger( true, static function ( $message, $level, $context ) {
 			return $level === Psr\Log\LogLevel::ERROR ? '1' : null;
 		}, true );
 		$command = $this->getPhpCommand( 'echo_args.php' );
diff --git a/tests/phpunit/includes/shell/ShellTest.php b/tests/phpunit/includes/shell/ShellTest.php
index b343a958e71..ef966abf09f 100644
--- a/tests/phpunit/includes/shell/ShellTest.php
+++ b/tests/phpunit/includes/shell/ShellTest.php
@@ -88,7 +88,7 @@ class ShellTest extends MediaWikiIntegrationTestCase {
 				'maintenance/foobar.php',
 				[ 'bar\'"baz' ],
 				[],
-				function ( &$script, array &$parameters ) {
+				static function ( &$script, array &$parameters ) {
 					$script = 'changed.php';
 					array_unshift( $parameters, '--wiki=somewiki' );
 				}
diff --git a/tests/phpunit/includes/site/SiteExporterTest.php b/tests/phpunit/includes/site/SiteExporterTest.php
index e5defa4c88a..128a812e2b9 100644
--- a/tests/phpunit/includes/site/SiteExporterTest.php
+++ b/tests/phpunit/includes/site/SiteExporterTest.php
@@ -76,7 +76,7 @@ class SiteExporterTest extends MediaWikiIntegrationTestCase {
 
 		$store->expects( $this->once() )
 			->method( 'saveSites' )
-			->will( $this->returnCallback( function ( $moreSites ) use ( $sites ) {
+			->will( $this->returnCallback( static function ( $moreSites ) use ( $sites ) {
 				foreach ( $moreSites as $site ) {
 					$sites->setSite( $site );
 				}
diff --git a/tests/phpunit/includes/specialpage/AbstractChangesListSpecialPageTestCase.php b/tests/phpunit/includes/specialpage/AbstractChangesListSpecialPageTestCase.php
index 543800ecf97..7e0cce514b7 100644
--- a/tests/phpunit/includes/specialpage/AbstractChangesListSpecialPageTestCase.php
+++ b/tests/phpunit/includes/specialpage/AbstractChangesListSpecialPageTestCase.php
@@ -98,7 +98,7 @@ abstract class AbstractChangesListSpecialPageTestCase extends MediaWikiIntegrati
 			->disableOriginalConstructor()
 			->getMock();
 		$output->method( 'redirect' )->willReturnCallback(
-			function ( $url ) use ( &$redirectQuery, &$redirected ) {
+			static function ( $url ) use ( &$redirectQuery, &$redirected ) {
 				$urlParts = wfParseUrl( $url );
 				$query = $urlParts[ 'query' ] ?? '';
 				parse_str( $query, $redirectQuery );
diff --git a/tests/phpunit/includes/specialpage/SpecialPageFactoryTest.php b/tests/phpunit/includes/specialpage/SpecialPageFactoryTest.php
index 47913bf1a4e..b3d83568e57 100644
--- a/tests/phpunit/includes/specialpage/SpecialPageFactoryTest.php
+++ b/tests/phpunit/includes/specialpage/SpecialPageFactoryTest.php
@@ -34,7 +34,7 @@ class SpecialPageFactoryTest extends MediaWikiIntegrationTestCase {
 		$count = 0;
 		$this->mergeMwGlobalArrayValue( 'wgHooks', [
 			'SpecialPage_initList' => [
-				function () use ( &$count ) {
+				static function () use ( &$count ) {
 					$count++;
 				}
 		] ] );
@@ -53,7 +53,7 @@ class SpecialPageFactoryTest extends MediaWikiIntegrationTestCase {
 
 		return [
 			'class name' => [ 'SpecialAllPages', false ],
-			'closure' => [ function () {
+			'closure' => [ static function () {
 				return new SpecialAllPages();
 			}, false ],
 			'function' => [ [ $this, 'newSpecialAllPages' ], false ],
@@ -265,7 +265,7 @@ class SpecialPageFactoryTest extends MediaWikiIntegrationTestCase {
 		$called = false;
 		$this->mergeMwGlobalArrayValue( 'wgHooks', [
 			'SpecialPage_initList' => [
-				function () use ( &$called ) {
+				static function () use ( &$called ) {
 					MediaWikiServices::getInstance()
 						->getSpecialPageFactory()
 						->getLocalNameFor( 'Specialpages' );
@@ -285,7 +285,7 @@ class SpecialPageFactoryTest extends MediaWikiIntegrationTestCase {
 
 		$this->setMwGlobals( 'wgSpecialPages',
 			[ 'TestPage' => [
-				'factory' => function ( $spf ) use ( &$type ) {
+				'factory' => static function ( $spf ) use ( &$type ) {
 					$type = get_class( $spf );
 
 					return new class() extends SpecialPage {
diff --git a/tests/phpunit/includes/specials/ContribsPagerTest.php b/tests/phpunit/includes/specials/ContribsPagerTest.php
index 962a52b08f9..a798c5ff26e 100644
--- a/tests/phpunit/includes/specials/ContribsPagerTest.php
+++ b/tests/phpunit/includes/specials/ContribsPagerTest.php
@@ -68,7 +68,7 @@ class ContribsPagerTest extends MediaWikiIntegrationTestCase {
 	 * extensions are able to insert their own revisions
 	 */
 	public function testRevisionsOnlyOption() {
-		$this->setTemporaryHook( 'ContribsPager::reallyDoQuery', function ( &$data ) {
+		$this->setTemporaryHook( 'ContribsPager::reallyDoQuery', static function ( &$data ) {
 			$fakeRow = (object)[ 'rev_timestamp' => '20200717192356' ];
 			$fakeRowWrapper = new FakeResultWrapper( [ $fakeRow ] );
 			$data[] = $fakeRowWrapper;
diff --git a/tests/phpunit/includes/specials/SpecialContributionsTest.php b/tests/phpunit/includes/specials/SpecialContributionsTest.php
index a30dbf28fef..1d172044e47 100644
--- a/tests/phpunit/includes/specials/SpecialContributionsTest.php
+++ b/tests/phpunit/includes/specials/SpecialContributionsTest.php
@@ -20,7 +20,7 @@ class SpecialContributionsTest extends SpecialPageTestBase {
 		] );
 		$this->setTemporaryHook(
 			'SpecialContributionsBeforeMainOutput',
-			function () {
+			static function () {
 				return;
 			}
 		);
diff --git a/tests/phpunit/includes/specials/SpecialSearchTest.php b/tests/phpunit/includes/specials/SpecialSearchTest.php
index 48bcda4cf96..549f1eb722a 100644
--- a/tests/phpunit/includes/specials/SpecialSearchTest.php
+++ b/tests/phpunit/includes/specials/SpecialSearchTest.php
@@ -420,7 +420,7 @@ class SpecialSearchTest extends MediaWikiIntegrationTestCase {
 			$languageConverter->expects( $this->once() )
 				->method( 'findVariantLink' )
 				->willReturnCallback(
-					function ( &$link, &$nt, $unused = false ) use ( $searchTerm, $variantTitle, $variantLink ) {
+					static function ( &$link, &$nt, $unused = false ) use ( $searchTerm, $variantTitle, $variantLink ) {
 						if ( $link === $searchTerm ) {
 							$link = $variantLink;
 							$nt = $variantTitle;
diff --git a/tests/phpunit/includes/title/MediaWikiTitleCodecTest.php b/tests/phpunit/includes/title/MediaWikiTitleCodecTest.php
index 53bdd8b792d..938c88fbc48 100644
--- a/tests/phpunit/includes/title/MediaWikiTitleCodecTest.php
+++ b/tests/phpunit/includes/title/MediaWikiTitleCodecTest.php
@@ -58,7 +58,7 @@ class MediaWikiTitleCodecTest extends MediaWikiIntegrationTestCase {
 
 		$genderCache->expects( $this->any() )
 			->method( 'getGenderOf' )
-			->will( $this->returnCallback( function ( $userName ) {
+			->will( $this->returnCallback( static function ( $userName ) {
 				return preg_match( '/^[^- _]+a( |_|$)/u', $userName ) ? 'female' : 'male';
 			} ) );
 
@@ -76,12 +76,12 @@ class MediaWikiTitleCodecTest extends MediaWikiIntegrationTestCase {
 
 		$iwLookup->expects( $this->any() )
 			->method( 'isValidInterwiki' )
-			->will( $this->returnCallback( function ( $prefix ) {
+			->will( $this->returnCallback( static function ( $prefix ) {
 				return $prefix === 'localtestiw' || $prefix === 'remotetestiw';
 			} ) );
 
 		$iwLookup->expects( $this->never() )
-			->method( $this->callback( function ( $name ) {
+			->method( $this->callback( static function ( $name ) {
 				return $name !== 'isValidInterwiki';
 			} ) );
 
@@ -114,17 +114,17 @@ class MediaWikiTitleCodecTest extends MediaWikiIntegrationTestCase {
 		$nsInfo = $this->createMock( NamespaceInfo::class );
 
 		$nsInfo->method( 'exists' )
-			->will( $this->returnCallback( function ( $ns ) use ( $canonicalNamespaces ) {
+			->will( $this->returnCallback( static function ( $ns ) use ( $canonicalNamespaces ) {
 				return isset( $canonicalNamespaces[$ns] );
 			} ) );
 
 		$nsInfo->method( 'getCanonicalName' )
-			->will( $this->returnCallback( function ( $ns ) use ( $canonicalNamespaces ) {
+			->will( $this->returnCallback( static function ( $ns ) use ( $canonicalNamespaces ) {
 				return $canonicalNamespaces[$ns] ?? false;
 			} ) );
 
 		$nsInfo->method( 'hasGenderDistinction' )
-			->will( $this->returnCallback( function ( $ns ) {
+			->will( $this->returnCallback( static function ( $ns ) {
 				return $ns === NS_USER || $ns === NS_USER_TALK;
 			} ) );
 
diff --git a/tests/phpunit/includes/title/NamespaceInfoTest.php b/tests/phpunit/includes/title/NamespaceInfoTest.php
index 9eaddf54669..b942fd8ab41 100644
--- a/tests/phpunit/includes/title/NamespaceInfoTest.php
+++ b/tests/phpunit/includes/title/NamespaceInfoTest.php
@@ -1226,7 +1226,7 @@ class NamespaceInfoTest extends MediaWikiIntegrationTestCase {
 	public function testGetValidNamespaces_misc( array $namespaces, array $expected ) {
 		// Each namespace's name is just its index
 		$this->setTemporaryHook( 'CanonicalNamespaces',
-			function ( &$canonicalNamespaces ) use ( $namespaces ) {
+			static function ( &$canonicalNamespaces ) use ( $namespaces ) {
 				$canonicalNamespaces = array_combine( $namespaces, $namespaces );
 			}
 		);
diff --git a/tests/phpunit/includes/user/BotPasswordTest.php b/tests/phpunit/includes/user/BotPasswordTest.php
index 002e5dfe4f9..f00d8cf480c 100644
--- a/tests/phpunit/includes/user/BotPasswordTest.php
+++ b/tests/phpunit/includes/user/BotPasswordTest.php
@@ -48,10 +48,10 @@ class BotPasswordTest extends MediaWikiIntegrationTestCase {
 		$mock2->expects( $this->never() )->method( 'lookupCentralIds' );
 
 		$this->mergeMwGlobalArrayValue( 'wgCentralIdLookupProviders', [
-			'BotPasswordTest OkMock' => [ 'factory' => function () use ( $mock1 ) {
+			'BotPasswordTest OkMock' => [ 'factory' => static function () use ( $mock1 ) {
 				return $mock1;
 			} ],
-			'BotPasswordTest FailMock' => [ 'factory' => function () use ( $mock2 ) {
+			'BotPasswordTest FailMock' => [ 'factory' => static function () use ( $mock2 ) {
 				return $mock2;
 			} ],
 		] );
diff --git a/tests/phpunit/includes/user/CentralIdLookupTest.php b/tests/phpunit/includes/user/CentralIdLookupTest.php
index 0350c06f6da..9ad3ca883f2 100644
--- a/tests/phpunit/includes/user/CentralIdLookupTest.php
+++ b/tests/phpunit/includes/user/CentralIdLookupTest.php
@@ -15,7 +15,7 @@ class CentralIdLookupTest extends MediaWikiIntegrationTestCase {
 			'wgCentralIdLookupProviders' => [
 				'local' => [ 'class' => LocalIdLookup::class ],
 				'local2' => [ 'class' => LocalIdLookup::class ],
-				'mock' => [ 'factory' => function () use ( $mock ) {
+				'mock' => [ 'factory' => static function () use ( $mock ) {
 					return $mock;
 				} ],
 				'bad' => [ 'class' => stdClass::class ],
diff --git a/tests/phpunit/includes/user/DefaultOptionsLookupTest.php b/tests/phpunit/includes/user/DefaultOptionsLookupTest.php
index c925b27d9bb..6f59564b0df 100644
--- a/tests/phpunit/includes/user/DefaultOptionsLookupTest.php
+++ b/tests/phpunit/includes/user/DefaultOptionsLookupTest.php
@@ -26,7 +26,7 @@ class DefaultOptionsLookupTest extends UserOptionsLookupTest {
 	 * @covers MediaWiki\User\DefaultOptionsLookup::getDefaultOptions
 	 */
 	public function testGetDefaultOptionsHook() {
-		$this->setTemporaryHook( 'UserGetDefaultOptions', function ( &$options ) {
+		$this->setTemporaryHook( 'UserGetDefaultOptions', static function ( &$options ) {
 			$options['from_hook'] = 'value_from_hook';
 		} );
 		$this->assertSame( 'value_from_hook', $this->getLookup()->getDefaultOption( 'from_hook' ) );
diff --git a/tests/phpunit/includes/user/PasswordResetTest.php b/tests/phpunit/includes/user/PasswordResetTest.php
index 47c2767b267..d0931510e7e 100644
--- a/tests/phpunit/includes/user/PasswordResetTest.php
+++ b/tests/phpunit/includes/user/PasswordResetTest.php
@@ -269,7 +269,7 @@ class PasswordResetTest extends MediaWikiIntegrationTestCase {
 		$userFactory = $this->createMock( UserFactory::class );
 		$userFactory->method( 'newFromName' )
 			->willReturnCallback(
-				function ( $username ) use ( $users ) {
+				static function ( $username ) use ( $users ) {
 					return $users[ $username ] ?? null;
 				}
 			);
@@ -656,7 +656,7 @@ class PasswordResetTest extends MediaWikiIntegrationTestCase {
 			->getMock();
 		$authManager->method( 'allowsAuthenticationDataChange' )
 			->willReturnCallback(
-				function ( TemporaryPasswordAuthenticationRequest $req )
+				static function ( TemporaryPasswordAuthenticationRequest $req )
 						use ( $allowed, $ignored, $mailThrottledLimited ) {
 					if ( in_array( $req->username, $mailThrottledLimited, true ) ) {
 						return Status::newGood( 'throttled-mailpassword' );
diff --git a/tests/phpunit/includes/user/TalkPageNotificationManagerTest.php b/tests/phpunit/includes/user/TalkPageNotificationManagerTest.php
index 345ad79b8b6..aa1460c655c 100644
--- a/tests/phpunit/includes/user/TalkPageNotificationManagerTest.php
+++ b/tests/phpunit/includes/user/TalkPageNotificationManagerTest.php
@@ -142,7 +142,7 @@ class TalkPageNotificationManagerTest extends MediaWikiIntegrationTestCase {
 			->willReturn( $veryOldTimestamp );
 		$mockRevLookup = $this->getMockForAbstractClass( RevisionLookup::class );
 		$mockRevLookup->method( 'getPreviousRevision' )
-			->willReturnCallback( function ( RevisionRecord $rev )
+			->willReturnCallback( static function ( RevisionRecord $rev )
 				use ( $firstRev, $secondRev, $thirdRev, $mockOldRev )
 			{
 				if ( $rev === $secondRev ) {
diff --git a/tests/phpunit/includes/user/UserNameUtilsTest.php b/tests/phpunit/includes/user/UserNameUtilsTest.php
index dad0c973008..768434ad07b 100644
--- a/tests/phpunit/includes/user/UserNameUtilsTest.php
+++ b/tests/phpunit/includes/user/UserNameUtilsTest.php
@@ -22,7 +22,7 @@ class UserNameUtilsTest extends MediaWikiIntegrationTestCase {
 			->disableOriginalConstructor()
 			->getMock();
 		$contentLang->method( 'ucfirst' )
-			->willReturnCallback( function ( $str ) {
+			->willReturnCallback( static function ( $str ) {
 				return ucfirst( $str );
 			} );
 		return $contentLang;
@@ -150,7 +150,7 @@ class UserNameUtilsTest extends MediaWikiIntegrationTestCase {
 	 * @covers MediaWiki\User\UserNameUtils::isCreatable
 	 */
 	public function testIsCreatable() {
-		$logger = new TestLogger( true, function ( $message ) {
+		$logger = new TestLogger( true, static function ( $message ) {
 			$message = str_replace(
 				'MediaWiki\\User\\UserNameUtils::isCreatable: ',
 				'',
diff --git a/tests/phpunit/includes/user/UserOptionsManagerTest.php b/tests/phpunit/includes/user/UserOptionsManagerTest.php
index 704038c73ab..d49b884c31c 100644
--- a/tests/phpunit/includes/user/UserOptionsManagerTest.php
+++ b/tests/phpunit/includes/user/UserOptionsManagerTest.php
@@ -103,7 +103,7 @@ class UserOptionsManagerTest extends UserOptionsLookupTest {
 		$user = $this->getTestUser()->getUser();
 		$this->setTemporaryHook(
 			'UserLoadOptions',
-			function ( User $hookUser, &$options ) use ( $user ) {
+			static function ( User $hookUser, &$options ) use ( $user ) {
 				if ( $hookUser->equals( $user ) ) {
 					$options['from_hook'] = 'value_from_hook';
 				}
@@ -119,7 +119,7 @@ class UserOptionsManagerTest extends UserOptionsLookupTest {
 		$user = $this->getTestUser()->getUser();
 		$this->setTemporaryHook(
 			'UserSaveOptions',
-			function () {
+			static function () {
 				return false;
 			}
 		);
@@ -136,7 +136,7 @@ class UserOptionsManagerTest extends UserOptionsLookupTest {
 		$user = $this->getTestUser()->getUser();
 		$this->setTemporaryHook(
 			'UserSaveOptions',
-			function ( User $hookUser, &$options ) use ( $user ) {
+			static function ( User $hookUser, &$options ) use ( $user ) {
 				if ( $hookUser->equals( $user ) ) {
 					$options['from_hook'] = 'value_from_hook';
 				}
@@ -181,7 +181,7 @@ class UserOptionsManagerTest extends UserOptionsLookupTest {
 		$manager = $this->getManager();
 		$this->setTemporaryHook(
 			'UserLoadOptions',
-			function ( User $hookUser, &$options ) use ( $user ) {
+			static function ( User $hookUser, &$options ) use ( $user ) {
 				if ( $hookUser->equals( $user ) ) {
 					$options['from_load_hook'] = 'from_load_hook';
 				}
diff --git a/tests/phpunit/includes/user/UserTest.php b/tests/phpunit/includes/user/UserTest.php
index 89e56ed94f8..066a6037677 100644
--- a/tests/phpunit/includes/user/UserTest.php
+++ b/tests/phpunit/includes/user/UserTest.php
@@ -151,7 +151,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		$this->assertNotContains( 'nukeworld', $rights, 'sanity check' );
 
 		// Add a hook manipulating the rights
-		$this->setTemporaryHook( 'UserGetRights', function ( $user, &$rights ) {
+		$this->setTemporaryHook( 'UserGetRights', static function ( $user, &$rights ) {
 			$rights[] = 'nukeworld';
 			$rights = array_diff( $rights, [ 'writetest' ] );
 		} );
@@ -576,7 +576,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		$this->assertFalse( $this->user->checkPasswordValidity( $this->user->getName() )->isGood() );
 		$this->assertTrue( $this->user->checkPasswordValidity( $this->user->getName() )->isOK() );
 
-		$this->setTemporaryHook( 'isValidPassword', function ( $password, &$result, $user ) {
+		$this->setTemporaryHook( 'isValidPassword', static function ( $password, &$result, $user ) {
 			$result = 'isValidPassword returned false';
 			return false;
 		} );
@@ -587,7 +587,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 
 		$this->removeTemporaryHook( 'isValidPassword' );
 
-		$this->setTemporaryHook( 'isValidPassword', function ( $password, &$result, $user ) {
+		$this->setTemporaryHook( 'isValidPassword', static function ( $password, &$result, $user ) {
 			$result = true;
 			return true;
 		} );
@@ -598,7 +598,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 
 		$this->removeTemporaryHook( 'isValidPassword' );
 
-		$this->setTemporaryHook( 'isValidPassword', function ( $password, &$result, $user ) {
+		$this->setTemporaryHook( 'isValidPassword', static function ( $password, &$result, $user ) {
 			$result = 'isValidPassword returned true';
 			return true;
 		} );
@@ -732,7 +732,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		$this->assertTrue( $user->isLoggedIn() ); // Deprecated wrapper method
 		$this->assertFalse( $user->isAnon() );
 
-		$this->setTemporaryHook( 'UserLogout', function ( &$user ) {
+		$this->setTemporaryHook( 'UserLogout', static function ( &$user ) {
 			return false;
 		} );
 		$user->logout();
@@ -1619,7 +1619,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testGetFirstLatestEditTimestamp() {
 		$clock = MWTimestamp::convert( TS_UNIX, '20100101000000' );
-		MWTimestamp::setFakeTime( function () use ( &$clock ) {
+		MWTimestamp::setFakeTime( static function () use ( &$clock ) {
 			return $clock += 1000;
 		} );
 		try {
@@ -1802,7 +1802,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 	public function testGetDefaultOptions() {
 		$this->resetServices();
 
-		$this->setTemporaryHook( 'UserGetDefaultOptions', function ( &$defaults ) {
+		$this->setTemporaryHook( 'UserGetDefaultOptions', static function ( &$defaults ) {
 			$defaults['extraoption'] = 42;
 		} );
 
@@ -1922,7 +1922,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		$this->assertTrue( $user->addGroup( 'test2' ) );
 		$this->assertArrayEquals( [ 'test', 'test2' ], $user->getGroups() );
 
-		$this->setTemporaryHook( 'UserAddGroup', function ( $user, &$group, &$expiry ) {
+		$this->setTemporaryHook( 'UserAddGroup', static function ( $user, &$group, &$expiry ) {
 			return false;
 		} );
 		$this->assertFalse( $user->addGroup( 'test3' ) );
@@ -1947,7 +1947,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 			'A group membership that does not exist cannot be removed'
 		);
 
-		$this->setTemporaryHook( 'UserRemoveGroup', function ( $user, &$group ) {
+		$this->setTemporaryHook( 'UserRemoveGroup', static function ( $user, &$group ) {
 			return false;
 		} );
 
@@ -2114,7 +2114,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 
 		$this->removeTemporaryHook( 'UserSetEmail' );
 
-		$this->setTemporaryHook( 'UserSetEmail', function ( $user, &$email ) {
+		$this->setTemporaryHook( 'UserSetEmail', static function ( $user, &$email ) {
 			$email = 'SettingIntercepted@mediawiki.org';
 		} );
 		$user->setEmail( 'NewEmail@mediawiki.org' );
@@ -2124,7 +2124,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 			'Hooks can override setting email addresses'
 		);
 
-		$this->setTemporaryHook( 'UserGetEmail', function ( $user, &$email ) {
+		$this->setTemporaryHook( 'UserGetEmail', static function ( $user, &$email ) {
 			$email = 'GettingIntercepted@mediawiki.org';
 		} );
 		$this->assertSame(
@@ -2219,7 +2219,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		$user->saveSettings();
 
 		$this->filterDeprecated( '/UserRequiresHTTPS hook/' );
-		$this->setTemporaryHook( 'UserRequiresHTTPS', function ( $user, &$https ) use ( $hook1 ) {
+		$this->setTemporaryHook( 'UserRequiresHTTPS', static function ( $user, &$https ) use ( $hook1 ) {
 			$https = $hook1;
 			return false;
 		} );
@@ -2370,7 +2370,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		// Hook leaves $result false
 		$this->setTemporaryHook(
 			'PingLimiter',
-			function ( &$user, $action, &$result, $incrBy ) {
+			static function ( &$user, $action, &$result, $incrBy ) {
 				return false;
 			}
 		);
@@ -2383,7 +2383,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		// Hook sets $result to true
 		$this->setTemporaryHook(
 			'PingLimiter',
-			function ( &$user, $action, &$result, $incrBy ) {
+			static function ( &$user, $action, &$result, $incrBy ) {
 				$result = true;
 				return false;
 			}
@@ -2423,7 +2423,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		ObjectCache::$instances[$wgMainCacheType] = $cache;
 
 		$cache->setMockTime( $cacheTime ); // this is a reference!
-		MWTimestamp::setFakeTime( function () use ( &$appTime ) {
+		MWTimestamp::setFakeTime( static function () use ( &$appTime ) {
 			return (int)$appTime;
 		} );
 
@@ -2461,7 +2461,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		ObjectCache::$instances[$wgMainCacheType] = $cache;
 
 		$cache->setMockTime( $fakeTime ); // this is a reference!
-		MWTimestamp::setFakeTime( function () use ( &$fakeTime ) {
+		MWTimestamp::setFakeTime( static function () use ( &$fakeTime ) {
 			return (int)$fakeTime;
 		} );
 
@@ -2648,7 +2648,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		// Make sure time progresses between revisions.
 		// MediaWikiIntegrationTestCase automatically restores the real clock.
 		$clock = MWTimestamp::time();
-		MWTimestamp::setFakeTime( function () use ( &$clock ) {
+		MWTimestamp::setFakeTime( static function () use ( &$clock ) {
 			return ++$clock;
 		} );
 
@@ -2676,7 +2676,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 		);
 
 		$mockCentralIdLookup->method( 'centralIdFromLocalUser' )
-			->willReturnCallback( function ( User $user ) {
+			->willReturnCallback( static function ( User $user ) {
 				return $user->getId() % 100;
 			} );
 
@@ -2684,7 +2684,7 @@ class UserTest extends MediaWikiIntegrationTestCase {
 			'wgCentralIdLookupProvider' => 'test',
 			'wgCentralIdLookupProviders' => [
 				'test' => [
-					'factory' => function () use ( $mockCentralIdLookup ) {
+					'factory' => static function () use ( $mockCentralIdLookup ) {
 						return $mockCentralIdLookup;
 					}
 				]
diff --git a/tests/phpunit/includes/utils/BatchRowUpdateTest.php b/tests/phpunit/includes/utils/BatchRowUpdateTest.php
index a0568e77218..5cb985d9d49 100644
--- a/tests/phpunit/includes/utils/BatchRowUpdateTest.php
+++ b/tests/phpunit/includes/utils/BatchRowUpdateTest.php
@@ -204,7 +204,7 @@ class BatchRowUpdateTest extends MediaWikiIntegrationTestCase {
 			->will( $this->consecutivelyReturnFromSelect( $retvals ) );
 		$db->expects( $this->any() )
 			->method( 'addQuotes' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				return "'$value'"; // not real quoting: doesn't matter in test
 			} ) );
 
diff --git a/tests/phpunit/includes/watcheditem/WatchedItemStoreIntegrationTest.php b/tests/phpunit/includes/watcheditem/WatchedItemStoreIntegrationTest.php
index 18033727ac9..b272211a58e 100644
--- a/tests/phpunit/includes/watcheditem/WatchedItemStoreIntegrationTest.php
+++ b/tests/phpunit/includes/watcheditem/WatchedItemStoreIntegrationTest.php
@@ -324,7 +324,7 @@ class WatchedItemStoreIntegrationTest extends MediaWikiIntegrationTestCase {
 
 		// setNotificationTimestampsForUser not specifying a title
 		// This will try to use a DeferredUpdate; disable that
-		$mockCallback = function ( $callback ) {
+		$mockCallback = static function ( $callback ) {
 			$callback();
 		};
 		$scopedOverride = $store->overrideDeferredUpdatesAddCallableUpdateCallback( $mockCallback );
@@ -369,7 +369,7 @@ class WatchedItemStoreIntegrationTest extends MediaWikiIntegrationTestCase {
 		$expectedExpiry2 = $store->loadWatchedItem( $user2, $titleOld )->getExpiry();
 
 		// Duplicate associated entries. This will try to use a DeferredUpdate; disable that.
-		$mockCallback = function ( $callback ) {
+		$mockCallback = static function ( $callback ) {
 			$callback();
 		};
 		$store->overrideDeferredUpdatesAddCallableUpdateCallback( $mockCallback );
diff --git a/tests/phpunit/includes/watcheditem/WatchedItemStoreUnitTest.php b/tests/phpunit/includes/watcheditem/WatchedItemStoreUnitTest.php
index 75392b48217..fd3f62d247e 100644
--- a/tests/phpunit/includes/watcheditem/WatchedItemStoreUnitTest.php
+++ b/tests/phpunit/includes/watcheditem/WatchedItemStoreUnitTest.php
@@ -82,12 +82,12 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 			->getMock();
 		$mock->expects( $this->any() )
 			->method( 'push' )
-			->will( $this->returnCallback( function ( Job $job ) {
+			->will( $this->returnCallback( static function ( Job $job ) {
 				$job->run();
 			} ) );
 		$mock->expects( $this->any() )
 			->method( 'lazyPush' )
-			->will( $this->returnCallback( function ( Job $job ) {
+			->will( $this->returnCallback( static function ( Job $job ) {
 				$job->run();
 			} ) );
 		return $mock;
@@ -103,7 +103,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 			->getMock();
 		$mock->expects( $this->any() )
 			->method( 'makeKey' )
-			->will( $this->returnCallback( function ( ...$args ) {
+			->will( $this->returnCallback( static function ( ...$args ) {
 				return implode( ':', $args );
 			} ) );
 		return $mock;
@@ -132,7 +132,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 		$mock = $this->createMock( NamespaceInfo::class );
 		$mock->method( 'getSubjectPage' )->will( $this->returnArgument( 0 ) );
 		$mock->method( 'getTalkPage' )->will( $this->returnCallback(
-				function ( $target ) {
+				static function ( $target ) {
 					return new TitleValue( 1, $target->getDbKey() );
 				}
 			) );
@@ -542,13 +542,13 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 
 		$mockDb->expects( $this->exactly( 2 ) )
 			->method( 'addQuotes' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				return "'$value'";
 			} ) );
 
 		$mockDb->expects( $this->exactly( 2 ) )
 			->method( 'timestamp' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				if ( $value === 0 ) {
 					return '20200101000000';
 				}
@@ -580,13 +580,13 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 		$mockDb = $this->getMockDb();
 		$mockDb->expects( $this->exactly( 2 * 3 + 1 ) )
 			->method( 'addQuotes' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				return "'$value'";
 			} ) );
 
 		$mockDb->expects( $this->exactly( 4 ) )
 			->method( 'timestamp' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				if ( $value === 0 ) {
 					return '20200101000000';
 				}
@@ -599,7 +599,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 				$this->isType( 'array' ),
 				$this->isType( 'int' )
 			)
-			->will( $this->returnCallback( function ( $a, $conj ) {
+			->will( $this->returnCallback( static function ( $a, $conj ) {
 				$sqlConj = $conj === LIST_AND ? ' AND ' : ' OR ';
 				return implode( $sqlConj, array_map( static function ( $s ) {
 					return '(' . $s . ')';
@@ -675,12 +675,12 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 		$mockDb = $this->getMockDb();
 		$mockDb->expects( $this->exactly( 2 * 3 ) )
 			->method( 'addQuotes' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				return "'$value'";
 			} ) );
 		$mockDb->expects( $this->exactly( 3 ) )
 			->method( 'timestamp' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				return 'TS' . $value . 'TS';
 			} ) );
 		$mockDb->expects( $this->any() )
@@ -689,7 +689,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 				$this->isType( 'array' ),
 				$this->isType( 'int' )
 			)
-			->will( $this->returnCallback( function ( $a, $conj ) {
+			->will( $this->returnCallback( static function ( $a, $conj ) {
 				$sqlConj = $conj === LIST_AND ? ' AND ' : ' OR ';
 				return implode( $sqlConj, array_map( static function ( $s ) {
 					return '(' . $s . ')';
@@ -2210,10 +2210,10 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 
 		// We don't care if these methods actually do anything here
 		$mockRevisionLookup = $this->getMockRevisionLookup( [
-			'getRevisionByTitle' => function () {
+			'getRevisionByTitle' => static function () {
 				return null;
 			},
-			'getTimestampFromId' => function () {
+			'getTimestampFromId' => static function () {
 				return '00000000000000';
 			},
 		] );
@@ -2252,10 +2252,10 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 
 		// We don't care if these methods actually do anything here
 		$mockRevisionLookup = $this->getMockRevisionLookup( [
-			'getRevisionByTitle' => function () {
+			'getRevisionByTitle' => static function () {
 				return null;
 			},
-			'getTimestampFromId' => function () {
+			'getTimestampFromId' => static function () {
 				return '00000000000000';
 			},
 		] );
@@ -2321,7 +2321,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 		$mockRevisionRecord = $this->createNoOpMock( RevisionRecord::class );
 
 		$mockRevisionLookup = $this->getMockRevisionLookup( [
-			'getTimestampFromId' => function () {
+			'getTimestampFromId' => static function () {
 				return '00000000000000';
 			},
 			'getRevisionById' => function ( $id, $flags ) use ( $oldid, $mockRevisionRecord ) {
@@ -2353,7 +2353,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 						$job,
 						$title,
 						$user->getId(),
-						function ( $time ) {
+						static function ( $time ) {
 							return $time === null;
 						}
 					);
@@ -2452,7 +2452,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 						$job,
 						$title,
 						$user->getId(),
-						function ( $time ) {
+						static function ( $time ) {
 							return $time !== null && $time > '20151212010101';
 						}
 					);
@@ -2544,7 +2544,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 						$job,
 						$title,
 						$user->getId(),
-						function ( $time ) {
+						static function ( $time ) {
 							return $time === null;
 						}
 					);
@@ -2644,7 +2644,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 						$job,
 						$title,
 						$user->getId(),
-						function ( $time ) {
+						static function ( $time ) {
 							return $time === '30151212010101';
 						}
 					);
@@ -2743,7 +2743,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 						$job,
 						$title,
 						$user->getId(),
-						function ( $time ) {
+						static function ( $time ) {
 							return $time === false;
 						}
 					);
@@ -2821,7 +2821,7 @@ class WatchedItemStoreUnitTest extends MediaWikiIntegrationTestCase {
 			->will( $this->returnValue( true ) );
 		$mockDb->expects( $this->exactly( 1 ) )
 			->method( 'timestamp' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				return 'TS' . $value . 'TS';
 			} ) );
 		$mockDb->expects( $this->once() )
diff --git a/tests/phpunit/integration/includes/Rest/Handler/CreationHandlerTest.php b/tests/phpunit/integration/includes/Rest/Handler/CreationHandlerTest.php
index 11cc04107b7..8916cf888f7 100644
--- a/tests/phpunit/integration/includes/Rest/Handler/CreationHandlerTest.php
+++ b/tests/phpunit/integration/includes/Rest/Handler/CreationHandlerTest.php
@@ -54,11 +54,11 @@ class CreationHandlerTest extends MediaWikiIntegrationTestCase {
 			->getMock();
 
 		$titleCodec->method( 'formatTitle' )
-			->willReturnCallback( function ( $namespace, $text ) {
+			->willReturnCallback( static function ( $namespace, $text ) {
 				return "ns:$namespace:" . ucfirst( $text );
 			} );
 		$titleCodec->method( 'splitTitleString' )
-			->willReturnCallback( function ( $text ) {
+			->willReturnCallback( static function ( $text ) {
 				return [
 					'interwiki' => '',
 					'fragment' => '',
diff --git a/tests/phpunit/integration/includes/Rest/Handler/LanguageLinksHandlerTest.php b/tests/phpunit/integration/includes/Rest/Handler/LanguageLinksHandlerTest.php
index cb575d3a36c..f7bdf0f7493 100644
--- a/tests/phpunit/integration/includes/Rest/Handler/LanguageLinksHandlerTest.php
+++ b/tests/phpunit/integration/includes/Rest/Handler/LanguageLinksHandlerTest.php
@@ -156,7 +156,7 @@ class LanguageLinksHandlerTest extends \MediaWikiIntegrationTestCase {
 			new LocalizedHttpException( new MessageValue( 'rest-permission-denied-title' ), 403 )
 		);
 		$this->executeHandler( $handler, $request, [ 'userCan' => false ], [], [], [],
-			$this->mockAnonAuthority( function ( string $permission, ?PageIdentity $target ) {
+			$this->mockAnonAuthority( static function ( string $permission, ?PageIdentity $target ) {
 				return $target && !preg_match( '/Forbidden/', $target->getDBkey() );
 			} ) );
 	}
diff --git a/tests/phpunit/integration/includes/Rest/Handler/UpdateHandlerTest.php b/tests/phpunit/integration/includes/Rest/Handler/UpdateHandlerTest.php
index 07a25139dc1..d1eb7844513 100644
--- a/tests/phpunit/integration/includes/Rest/Handler/UpdateHandlerTest.php
+++ b/tests/phpunit/integration/includes/Rest/Handler/UpdateHandlerTest.php
@@ -62,11 +62,11 @@ class UpdateHandlerTest extends \MediaWikiLangTestCase {
 			->getMock();
 
 		$titleCodec->method( 'formatTitle' )
-			->willReturnCallback( function ( $namespace, $text ) {
+			->willReturnCallback( static function ( $namespace, $text ) {
 				return "ns:$namespace:" . ucfirst( $text );
 			} );
 		$titleCodec->method( 'splitTitleString' )
-			->willReturnCallback( function ( $text ) {
+			->willReturnCallback( static function ( $text ) {
 				return [
 					'interwiki' => '',
 					'fragment' => '',
@@ -89,7 +89,7 @@ class UpdateHandlerTest extends \MediaWikiLangTestCase {
 				return $rev;
 			} );
 		$revisionLookup->method( 'getRevisionByTitle' )
-			->willReturnCallback( function ( $title ) {
+			->willReturnCallback( static function ( $title ) {
 				$rev = new MutableRevisionRecord( Title::castFromLinkTarget( $title ) );
 				$rev->setId( 1234 );
 				$rev->setContent( SlotRecord::MAIN, new WikitextContent( "Current content of $title" ) );
diff --git a/tests/phpunit/integration/includes/TemplateParserIntegrationTest.php b/tests/phpunit/integration/includes/TemplateParserIntegrationTest.php
index 64577130ea9..693dfeeb807 100644
--- a/tests/phpunit/integration/includes/TemplateParserIntegrationTest.php
+++ b/tests/phpunit/integration/includes/TemplateParserIntegrationTest.php
@@ -44,7 +44,7 @@ class TemplateParserIntegrationTest extends MediaWikiIntegrationTestCase {
 		$cache1 = $this->createMock( BagOStuff::class );
 		$cache1->expects( $this->once() )->method( 'get' )->willReturn( false );
 		$cache1->expects( $this->once() )->method( 'set' )
-			->will( $this->returnCallback( function ( $key, $val ) use ( &$store ) {
+			->will( $this->returnCallback( static function ( $key, $val ) use ( &$store ) {
 				$store = [ 'key' => $key, 'val' => $val ];
 			} ) );
 
@@ -78,7 +78,7 @@ class TemplateParserIntegrationTest extends MediaWikiIntegrationTestCase {
 		// 2. Expect a cache hit that passes validation checks, and no compilation
 		$cache2 = $this->createMock( BagOStuff::class );
 		$cache2->expects( $this->once() )->method( 'get' )
-			->will( $this->returnCallback( function ( $key ) use ( &$store ) {
+			->will( $this->returnCallback( static function ( $key ) use ( &$store ) {
 				return $key === $store['key'] ? $store['val'] : false;
 			} ) );
 		$cache2->expects( $this->never() )->method( 'set' );
@@ -102,7 +102,7 @@ class TemplateParserIntegrationTest extends MediaWikiIntegrationTestCase {
 		$cache1 = $this->createMock( BagOStuff::class );
 		$cache1->expects( $this->once() )->method( 'get' )->willReturn( false );
 		$cache1->expects( $this->once() )->method( 'set' )
-			->will( $this->returnCallback( function ( $key, $val ) use ( &$store ) {
+			->will( $this->returnCallback( static function ( $key, $val ) use ( &$store ) {
 				$store = [ 'key' => $key, 'val' => $val ];
 			} ) );
 
@@ -115,7 +115,7 @@ class TemplateParserIntegrationTest extends MediaWikiIntegrationTestCase {
 		// 2. Expect a cache hit that fails validation, and a re-compilation
 		$cache2 = $this->createMock( BagOStuff::class );
 		$cache2->expects( $this->once() )->method( 'get' )
-			->will( $this->returnCallback( function ( $key ) use ( &$store ) {
+			->will( $this->returnCallback( static function ( $key ) use ( &$store ) {
 				return $key === $store['key'] ? $store['val'] : false;
 			} ) );
 		$cache2->expects( $this->once() )->method( 'set' );
@@ -140,7 +140,7 @@ class TemplateParserIntegrationTest extends MediaWikiIntegrationTestCase {
 		$cache1 = $this->createMock( BagOStuff::class );
 		$cache1->expects( $this->once() )->method( 'get' )->willReturn( false );
 		$cache1->expects( $this->once() )->method( 'set' )
-			->will( $this->returnCallback( function ( $key, $val ) use ( &$store ) {
+			->will( $this->returnCallback( static function ( $key, $val ) use ( &$store ) {
 				$store = [ 'key' => $key, 'val' => $val ];
 			} ) );
 
@@ -153,7 +153,7 @@ class TemplateParserIntegrationTest extends MediaWikiIntegrationTestCase {
 		// 2. Expect a cache hit that fails validation, and a re-compilation
 		$cache2 = $this->createMock( BagOStuff::class );
 		$cache2->expects( $this->once() )->method( 'get' )
-			->will( $this->returnCallback( function ( $key ) use ( &$store ) {
+			->will( $this->returnCallback( static function ( $key ) use ( &$store ) {
 				return $key === $store['key'] ? $store['val'] : false;
 			} ) );
 		$cache2->expects( $this->once() )->method( 'set' );
@@ -301,7 +301,7 @@ class TemplateParserIntegrationTest extends MediaWikiIntegrationTestCase {
 		$cache = $this->createMock( BagOStuff::class );
 		$cache->expects( $this->once() )->method( 'get' )->willReturn( false );
 		$cache->expects( $this->once() )->method( 'set' )
-			->will( $this->returnCallback( function ( $key, $val ) use ( &$store ) {
+			->will( $this->returnCallback( static function ( $key, $val ) use ( &$store ) {
 				$store = [ 'key' => $key, 'val' => $val ];
 			} ) );
 		$tp = new TemplateParser( self::DIR, $cache );
diff --git a/tests/phpunit/integration/includes/db/DatabaseSqliteTest.php b/tests/phpunit/integration/includes/db/DatabaseSqliteTest.php
index 35122f3c764..55468a27a67 100644
--- a/tests/phpunit/integration/includes/db/DatabaseSqliteTest.php
+++ b/tests/phpunit/integration/includes/db/DatabaseSqliteTest.php
@@ -66,7 +66,7 @@ class DatabaseSqliteTest extends \MediaWikiIntegrationTestCase {
 		$mock->initConnection();
 
 		$sqlDump = '';
-		$mock->method( 'query' )->willReturnCallback( function ( $sql ) use ( &$sqlDump ) {
+		$mock->method( 'query' )->willReturnCallback( static function ( $sql ) use ( &$sqlDump ) {
 			$sqlDump .= "$sql;";
 
 			return true;
diff --git a/tests/phpunit/languages/LanguageConverterFactoryTest.php b/tests/phpunit/languages/LanguageConverterFactoryTest.php
index 75ec5a84990..89723355ac1 100644
--- a/tests/phpunit/languages/LanguageConverterFactoryTest.php
+++ b/tests/phpunit/languages/LanguageConverterFactoryTest.php
@@ -26,7 +26,7 @@ class LanguageConverterFactoryTest extends MediaWikiLangTestCase {
 		$manualLevel
 	) {
 		$lang = MediaWikiServices::getInstance()->getLanguageFactory()->getLanguage( $code );
-		$factory = new LanguageConverterFactory( false, false, false, function () use ( $lang ) {
+		$factory = new LanguageConverterFactory( false, false, false, static function () use ( $lang ) {
 			return $lang;
 		} );
 		$this->assertFalse( $factory->isConversionDisabled() );
@@ -53,7 +53,7 @@ class LanguageConverterFactoryTest extends MediaWikiLangTestCase {
 	 */
 	public function testCreateFromCodeEnPigLatin() {
 		$lang = MediaWikiServices::getInstance()->getLanguageFactory()->getLanguage( 'en' );
-		$factory = new LanguageConverterFactory( true, false, false, function () use ( $lang ) {
+		$factory = new LanguageConverterFactory( true, false, false, static function () use ( $lang ) {
 			return $lang;
 		} );
 		$this->assertFalse( $factory->isConversionDisabled() );
@@ -87,7 +87,7 @@ class LanguageConverterFactoryTest extends MediaWikiLangTestCase {
 			!$pigLatinDisabled,
 			$conversionDisabled,
 			$titleDisabled,
-			function () use ( $lang ) {
+			static function () use ( $lang ) {
 				return $lang;
 			}
 		);
@@ -128,7 +128,7 @@ class LanguageConverterFactoryTest extends MediaWikiLangTestCase {
 	 */
 	public function testDefaultContentLanguageFallback() {
 		$lang = MediaWikiServices::getInstance()->getLanguageFactory()->getLanguage( 'en' );
-		$factory = new LanguageConverterFactory( false, false, false, function () use ( $lang ) {
+		$factory = new LanguageConverterFactory( false, false, false, static function () use ( $lang ) {
 			return $lang;
 		} );
 		$this->assertFalse( $factory->isConversionDisabled() );
diff --git a/tests/phpunit/languages/LanguageConverterIntegrationTest.php b/tests/phpunit/languages/LanguageConverterIntegrationTest.php
index 37c608be3c2..4353174b0c9 100644
--- a/tests/phpunit/languages/LanguageConverterIntegrationTest.php
+++ b/tests/phpunit/languages/LanguageConverterIntegrationTest.php
@@ -13,7 +13,7 @@ class LanguageConverterIntegrationTest extends MediaWikiIntegrationTestCase {
 
 	protected function setUp() : void {
 		parent::setUp();
-		$this->factory = new LanguageConverterFactory( false, false, false, function () {
+		$this->factory = new LanguageConverterFactory( false, false, false, static function () {
 			$language = MediaWikiServices::getInstance()->getContentLanguage();
 		} );
 	}
diff --git a/tests/phpunit/languages/LanguageConverterTest.php b/tests/phpunit/languages/LanguageConverterTest.php
index b2a83d10506..68521b24b14 100644
--- a/tests/phpunit/languages/LanguageConverterTest.php
+++ b/tests/phpunit/languages/LanguageConverterTest.php
@@ -34,7 +34,7 @@ class LanguageConverterTest extends MediaWikiLangTestCase {
 
 		$this->lang = $this->createMock( Language::class );
 		$this->lang->method( 'getNsText' )->with( NS_MEDIAWIKI )->willReturn( 'MediaWiki' );
-		$this->lang->method( 'ucfirst' )->will( $this->returnCallback( function ( $s ) {
+		$this->lang->method( 'ucfirst' )->will( $this->returnCallback( static function ( $s ) {
 			return ucfirst( $s );
 		} ) );
 		$this->lang->expects( $this->never() )
diff --git a/tests/phpunit/languages/LanguageConverterTestTrait.php b/tests/phpunit/languages/LanguageConverterTestTrait.php
index 1772f3b5944..749e166b94d 100644
--- a/tests/phpunit/languages/LanguageConverterTestTrait.php
+++ b/tests/phpunit/languages/LanguageConverterTestTrait.php
@@ -24,7 +24,7 @@ trait LanguageConverterTestTrait {
 		$language = MediaWikiServices::getInstance()->getLanguageFactory()
 			->getLanguage( $code );
 
-		$factory = new LanguageConverterFactory( false, false, false, function () use ( $language ) {
+		$factory = new LanguageConverterFactory( false, false, false, static function () use ( $language ) {
 			return $language;
 		} );
 
diff --git a/tests/phpunit/languages/LanguageIntegrationTest.php b/tests/phpunit/languages/LanguageIntegrationTest.php
index b4d1504fa19..aaa91d7cd4f 100644
--- a/tests/phpunit/languages/LanguageIntegrationTest.php
+++ b/tests/phpunit/languages/LanguageIntegrationTest.php
@@ -1916,7 +1916,7 @@ class LanguageIntegrationTest extends LanguageClassesTestCase {
 			->setMethods( [ 'getMessagesFileName' ] )
 			->getMock();
 		$langNameUtils->method( 'getMessagesFileName' )->will(
-			$this->returnCallback( function ( $code ) {
+			$this->returnCallback( static function ( $code ) {
 				return __DIR__ . '/../data/messages/Messages_' . $code . '.php';
 			} )
 		);
diff --git a/tests/phpunit/maintenance/BenchmarkerTest.php b/tests/phpunit/maintenance/BenchmarkerTest.php
index 7f9ed681652..06f85f88b22 100644
--- a/tests/phpunit/maintenance/BenchmarkerTest.php
+++ b/tests/phpunit/maintenance/BenchmarkerTest.php
@@ -22,7 +22,7 @@ class BenchmarkerTest extends \PHPUnit\Framework\TestCase {
 
 		$count = 0;
 		$bench->bench( [
-			'test' => function () use ( &$count ) {
+			'test' => static function () use ( &$count ) {
 					$count++;
 			}
 		] );
@@ -40,10 +40,10 @@ class BenchmarkerTest extends \PHPUnit\Framework\TestCase {
 		$buffer = [];
 		$bench->bench( [
 			'test' => [
-				'setup' => function () use ( &$buffer ) {
+				'setup' => static function () use ( &$buffer ) {
 						$buffer[] = 'setup';
 				},
-				'function' => function () use ( &$buffer ) {
+				'function' => static function () use ( &$buffer ) {
 						$buffer[] = 'run';
 				}
 			]
@@ -86,7 +86,7 @@ class BenchmarkerTest extends \PHPUnit\Framework\TestCase {
 		$benchProxy->defaultCount = 1;
 
 		$bench->expects( $this->once() )->method( 'addResult' )
-			->with( $this->callback( function ( $res ) {
+			->with( $this->callback( static function ( $res ) {
 				return isset( $res['name'] ) && $res['name'] === ( __CLASS__ . '::noop()' );
 			} ) );
 
@@ -103,7 +103,7 @@ class BenchmarkerTest extends \PHPUnit\Framework\TestCase {
 		$benchProxy->defaultCount = 1;
 
 		$bench->expects( $this->once() )->method( 'addResult' )
-			->with( $this->callback( function ( $res ) {
+			->with( $this->callback( static function ( $res ) {
 				return $res['name'] === 'strtolower(A)';
 			} ) );
 
@@ -130,7 +130,7 @@ class BenchmarkerTest extends \PHPUnit\Framework\TestCase {
 				] ) );
 
 		$bench->expects( $this->once() )->method( 'output' )
-			->with( $this->callback( function ( $out ) {
+			->with( $this->callback( static function ( $out ) {
 				return preg_match( '/memory.+ peak/', $out ) === 1;
 			} ) );
 
diff --git a/tests/phpunit/mocks/MockHttpTrait.php b/tests/phpunit/mocks/MockHttpTrait.php
index b414e6abb5f..23d7d93f149 100644
--- a/tests/phpunit/mocks/MockHttpTrait.php
+++ b/tests/phpunit/mocks/MockHttpTrait.php
@@ -93,7 +93,7 @@ trait MockHttpTrait {
 			'HTTPMaxConnectTimeout' => 1,
 		] );
 
-		$failCallback = function ( /* discard any arguments */ ) {
+		$failCallback = static function ( /* discard any arguments */ ) {
 			TestCase::fail( 'method should not be called' );
 		};
 
@@ -174,14 +174,14 @@ trait MockHttpTrait {
 
 		$mockHttpRequest->method( 'getResponseHeaders' )->willReturn( $headers );
 		$mockHttpRequest->method( 'getResponseHeader' )->willReturnCallback(
-			function ( $name ) use ( $headers ) {
+			static function ( $name ) use ( $headers ) {
 				return $headers[$name] ?? null;
 			}
 		);
 
 		$dataCallback = null;
 		$mockHttpRequest->method( 'setCallback' )->willReturnCallback(
-			function ( $callback ) use ( &$dataCallback ) {
+			static function ( $callback ) use ( &$dataCallback ) {
 				$dataCallback = $callback;
 			}
 		);
@@ -229,13 +229,13 @@ trait MockHttpTrait {
 		);
 
 		$mockHttpRequestMulti->method( 'run' )->willReturnCallback(
-			function ( array $req, array $opts = [] ) use ( $mockHttpRequestMulti ) {
+			static function ( array $req, array $opts = [] ) use ( $mockHttpRequestMulti ) {
 				return $mockHttpRequestMulti->runMulti( [ $req ], $opts )[0]['response'];
 			}
 		);
 
 		$mockHttpRequestMulti->method( 'runMulti' )->willReturnCallback(
-			function ( array $reqs, array $opts = [] ) use ( $responses ) {
+			static function ( array $reqs, array $opts = [] ) use ( $responses ) {
 				foreach ( $reqs as $key => &$req ) {
 					$resp = $responses[$key] ?? [ 'code' => 0, 'error' => 'unknown' ];
 
diff --git a/tests/phpunit/mocks/MockTitleTrait.php b/tests/phpunit/mocks/MockTitleTrait.php
index 43994ae82e5..f886a0b48a9 100644
--- a/tests/phpunit/mocks/MockTitleTrait.php
+++ b/tests/phpunit/mocks/MockTitleTrait.php
@@ -46,10 +46,10 @@ trait MockTitleTrait {
 		$title->method( 'getTouched' )->willReturn( $id ? '20200101223344' : false );
 		$title->method( 'getPageLanguage' )->willReturn( $props['language'] ?? 'qqx' );
 		$title->method( 'getRestrictions' )->willReturn( [] );
-		$title->method( 'isSamePageAs' )->willReturnCallback( function ( $other ) use ( $id ) {
+		$title->method( 'isSamePageAs' )->willReturnCallback( static function ( $other ) use ( $id ) {
 			return $other && $id === $other->getArticleId();
 		} );
-		$title->method( 'isSameLinkAs' )->willReturnCallback( function ( $other ) use ( $ns, $text ) {
+		$title->method( 'isSameLinkAs' )->willReturnCallback( static function ( $other ) use ( $ns, $text ) {
 			return $other && $text === $other->getDBkey() && $ns === $other->getNamespace();
 		} );
 
diff --git a/tests/phpunit/mocks/permissions/MockAuthorityTrait.php b/tests/phpunit/mocks/permissions/MockAuthorityTrait.php
index a9765d0cbeb..e7a3ada3c79 100644
--- a/tests/phpunit/mocks/permissions/MockAuthorityTrait.php
+++ b/tests/phpunit/mocks/permissions/MockAuthorityTrait.php
@@ -111,7 +111,7 @@ trait MockAuthorityTrait {
 			$mock->method( $method )->willReturnCallback( $permissionCallback );
 		}
 		$mock->method( 'isAllowedAny' )
-			->willReturnCallback( function ( ...$permissions ) use ( $permissionCallback ) {
+			->willReturnCallback( static function ( ...$permissions ) use ( $permissionCallback ) {
 				foreach ( $permissions as $permission ) {
 					if ( $permissionCallback( $permission ) ) {
 						return true;
@@ -120,7 +120,7 @@ trait MockAuthorityTrait {
 				return false;
 			} );
 		$mock->method( 'isAllowedAll' )
-			->willReturnCallback( function ( ...$permissions ) use ( $permissionCallback ) {
+			->willReturnCallback( static function ( ...$permissions ) use ( $permissionCallback ) {
 				foreach ( $permissions as $permission ) {
 					if ( $permissionCallback( $permission ) ) {
 						return false;
diff --git a/tests/phpunit/suites/ParsoidTestFileSuite.php b/tests/phpunit/suites/ParsoidTestFileSuite.php
index 9dfc2f3bb07..81f44d7565d 100644
--- a/tests/phpunit/suites/ParsoidTestFileSuite.php
+++ b/tests/phpunit/suites/ParsoidTestFileSuite.php
@@ -24,7 +24,7 @@ class ParsoidTestFileSuite extends TestSuite {
 		parent::__construct( $name );
 		$this->ptRunner = $runner;
 		$this->ptFileName = $fileName;
-		$this->ptFileInfo = Wikimedia\Parsoid\ParserTests\TestFileReader::read( $fileName, function ( $msg ) {
+		$this->ptFileInfo = Wikimedia\Parsoid\ParserTests\TestFileReader::read( $fileName, static function ( $msg ) {
 			wfDeprecatedMsg( $msg, '1.35', false, false );
 		} );
 		$fileOptions = $this->ptFileInfo->fileOptions;
diff --git a/tests/phpunit/tests/MediaWikiIntegrationTestCaseTest.php b/tests/phpunit/tests/MediaWikiIntegrationTestCaseTest.php
index 1602eec32f9..60141a58dae 100644
--- a/tests/phpunit/tests/MediaWikiIntegrationTestCaseTest.php
+++ b/tests/phpunit/tests/MediaWikiIntegrationTestCaseTest.php
@@ -249,7 +249,7 @@ class MediaWikiIntegrationTestCaseTest extends MediaWikiIntegrationTestCase {
 			->disableOriginalConstructor()
 			->getMock();
 		$this->setService( 'ReadOnlyMode', $myReadOnlyMode );
-		$this->setTemporaryHook( 'MyTestHook', function ( &$n ) {
+		$this->setTemporaryHook( 'MyTestHook', static function ( &$n ) {
 			$n++;
 		}, true );
 
@@ -259,7 +259,7 @@ class MediaWikiIntegrationTestCaseTest extends MediaWikiIntegrationTestCase {
 		// define a custom service
 		$services->defineService(
 			'_TEST_ResetService_Dummy',
-			function ( MediaWikiServices $services ) {
+			static function ( MediaWikiServices $services ) {
 				$conf = $services->getMainConfig();
 				return (object)[ 'lang' => $conf->get( 'LanguageCode' ) ];
 			}
@@ -303,7 +303,7 @@ class MediaWikiIntegrationTestCaseTest extends MediaWikiIntegrationTestCase {
 		$hookContainer = $this->getServiceContainer()->getHookContainer();
 		$name = 'MWITCT_Dummy_Hook';
 
-		$inc = function ( &$n ) {
+		$inc = static function ( &$n ) {
 			$n++;
 		};
 
diff --git a/tests/phpunit/unit/includes/BadFileLookupTest.php b/tests/phpunit/unit/includes/BadFileLookupTest.php
index e9913c06e7b..fba9a06a7e0 100644
--- a/tests/phpunit/unit/includes/BadFileLookupTest.php
+++ b/tests/phpunit/unit/includes/BadFileLookupTest.php
@@ -52,7 +52,7 @@ WIKITEXT;
 			->will( $this->returnCallback( function ( $name ) {
 				$mockFile = $this->createMock( File::class );
 				$mockFile->expects( $this->once() )->method( 'getTitle' )
-					->will( $this->returnCallback( function () use ( $name ) {
+					->will( $this->returnCallback( static function () use ( $name ) {
 						switch ( $name ) {
 							case 'Redirect to bad.jpg':
 								return new TitleValue( NS_FILE, 'Bad.jpg' );
diff --git a/tests/phpunit/unit/includes/HookContainer/HookContainerTest.php b/tests/phpunit/unit/includes/HookContainer/HookContainerTest.php
index 80ca3bc4227..d5339c3fa9f 100644
--- a/tests/phpunit/unit/includes/HookContainer/HookContainerTest.php
+++ b/tests/phpunit/unit/includes/HookContainer/HookContainerTest.php
@@ -71,10 +71,10 @@ namespace MediaWiki\HookContainer {
 					'MWTestHook',
 					[ $fooObj, 'MediaWiki\HookContainer\FooClass::FooMethod' ]
 				],
-				'Closure' => [ 'MWTestHook', function () {
+				'Closure' => [ 'MWTestHook', static function () {
 					return true;
 				} ],
-				'Closure with data' => [ 'MWTestHook', function () {
+				'Closure with data' => [ 'MWTestHook', static function () {
 					return true;
 				}, [ 'data' ] ]
 			];
@@ -114,7 +114,7 @@ namespace MediaWiki\HookContainer {
 		public static function provideRunLegacyErrors() {
 			return [
 				[ 123 ],
-				[ function () {
+				[ static function () {
 					return 'string';
 				} ]
 			];
@@ -175,12 +175,12 @@ namespace MediaWiki\HookContainer {
 			$hookContainer = $this->newHookContainer();
 			$called1 = $called2 = false;
 			$reset1 = $hookContainer->scopedRegister( 'MWTestHook',
-				function () use ( &$called1 ) {
+				static function () use ( &$called1 ) {
 					$called1 = true;
 				}, false
 			);
 			$reset2 = $hookContainer->scopedRegister( 'MWTestHook',
-				function () use ( &$called2 ) {
+				static function () use ( &$called2 ) {
 					$called2 = true;
 				}, false
 			);
@@ -208,10 +208,10 @@ namespace MediaWiki\HookContainer {
 		public function testHandlersRegisteredWithScopedRegisterAndRegister() {
 			$hookContainer = $this->newHookContainer();
 			$numCalls = 0;
-			$hookContainer->register( 'MWTestHook', function () use ( &$numCalls ) {
+			$hookContainer->register( 'MWTestHook', static function () use ( &$numCalls ) {
 				$numCalls++;
 			} );
-			$reset = $hookContainer->scopedRegister( 'MWTestHook', function () use ( &$numCalls ) {
+			$reset = $hookContainer->scopedRegister( 'MWTestHook', static function () use ( &$numCalls ) {
 				$numCalls++;
 			} );
 
@@ -388,7 +388,7 @@ namespace MediaWiki\HookContainer {
 		 */
 		public function testIsRegistered() {
 			$hookContainer = $this->newHookContainer();
-			$hookContainer->register( 'FooActionComplete', function () {
+			$hookContainer->register( 'FooActionComplete', static function () {
 				return true;
 			} );
 			$isRegistered = $hookContainer->isRegistered( 'FooActionComplete' );
@@ -467,7 +467,7 @@ namespace MediaWiki\HookContainer {
 					'class' => 'FooExtension\Hooks'
 				] ] ] ]
 			);
-			$hookContainer->register( 'Increment', function ( &$count ) {
+			$hookContainer->register( 'Increment', static function ( &$count ) {
 				$count++;
 			} );
 
@@ -486,7 +486,7 @@ namespace MediaWiki\HookContainer {
 			$this->assertFalse( $hookContainer->isRegistered( 'Increment' ) );
 
 			// When adding a handler again...
-			$hookContainer->register( 'Increment', function ( &$count ) {
+			$hookContainer->register( 'Increment', static function ( &$count ) {
 				$count = 11;
 			} );
 
@@ -508,7 +508,7 @@ namespace MediaWiki\HookContainer {
 					'class' => 'FooExtension\Hooks'
 				] ] ] ]
 			);
-			$hookContainer->register( 'Increment', function ( &$count ) {
+			$hookContainer->register( 'Increment', static function ( &$count ) {
 				$count++;
 			} );
 
@@ -519,7 +519,7 @@ namespace MediaWiki\HookContainer {
 			$this->assertTrue( $hookContainer->isRegistered( 'Increment' ) );
 
 			// Adding a scoped handler, with the $replace flag set.
-			$scope1 = $hookContainer->scopedRegister( 'Increment', function ( &$count ) {
+			$scope1 = $hookContainer->scopedRegister( 'Increment', static function ( &$count ) {
 				$count -= 3;
 			}, true );
 
@@ -530,7 +530,7 @@ namespace MediaWiki\HookContainer {
 			$this->assertTrue( $hookContainer->isRegistered( 'Increment' ) );
 
 			// Adding another permanent handler should work...
-			$hookContainer->register( 'Increment', function ( &$count ) {
+			$hookContainer->register( 'Increment', static function ( &$count ) {
 				$count++;
 			} );
 
@@ -540,7 +540,7 @@ namespace MediaWiki\HookContainer {
 			$this->assertSame( -2, $count );
 
 			// Adding another scoped handler, with the $replace flag set.
-			$scope2 = $hookContainer->scopedRegister( 'Increment', function ( &$count ) {
+			$scope2 = $hookContainer->scopedRegister( 'Increment', static function ( &$count ) {
 				$count -= 10;
 			}, true );
 
diff --git a/tests/phpunit/unit/includes/Permissions/PermissionManagerTest.php b/tests/phpunit/unit/includes/Permissions/PermissionManagerTest.php
index 23b89681027..ac44d8dcd65 100644
--- a/tests/phpunit/unit/includes/Permissions/PermissionManagerTest.php
+++ b/tests/phpunit/unit/includes/Permissions/PermissionManagerTest.php
@@ -349,14 +349,14 @@ class PermissionManagerTest extends MediaWikiUnitTestCase {
 		$namespaceInfo = $this->createMock( NamespaceInfo::class );
 		$namespaceInfo->method( 'isTalk' )
 			->willReturnCallback(
-				function ( $ns ) {
+				static function ( $ns ) {
 					return ( $ns > NS_MAIN && $ns % 2 === 1 );
 				}
 			);
 		$namespaceInfo->method( 'hasSubpages' )
 			->willReturnCallback(
 				// Only matters for user pages
-				function ( $ns ) {
+				static function ( $ns ) {
 					return ( $ns === NS_USER );
 				}
 			);
diff --git a/tests/phpunit/unit/includes/Permissions/UserAuthorityTest.php b/tests/phpunit/unit/includes/Permissions/UserAuthorityTest.php
index 63aee060126..271e179cb98 100644
--- a/tests/phpunit/unit/includes/Permissions/UserAuthorityTest.php
+++ b/tests/phpunit/unit/includes/Permissions/UserAuthorityTest.php
@@ -44,19 +44,19 @@ class UserAuthorityTest extends MediaWikiUnitTestCase {
 		);
 
 		$manager->method( 'userHasRight' )->willReturnCallback(
-			function ( $user, $permission ) use ( $permissions ) {
+			static function ( $user, $permission ) use ( $permissions ) {
 				return in_array( $permission, $permissions );
 			}
 		);
 
 		$manager->method( 'userCan' )->willReturnCallback(
-			function ( $permission, $user ) use ( $manager ) {
+			static function ( $permission, $user ) use ( $manager ) {
 				return $manager->userHasRight( $user, $permission );
 			}
 		);
 
 		$manager->method( 'getPermissionErrors' )->willReturnCallback(
-			function ( $permission, $user, $target ) use ( $manager ) {
+			static function ( $permission, $user, $target ) use ( $manager ) {
 				$errors = [];
 				if ( !$manager->userCan( $permission, $user, $target ) ) {
 					$errors[] = [ 'permissionserrors' ];
diff --git a/tests/phpunit/unit/includes/Rest/Handler/ActionModuleBasedHandlerTestTrait.php b/tests/phpunit/unit/includes/Rest/Handler/ActionModuleBasedHandlerTestTrait.php
index 88397d1eb23..760c5c954de 100644
--- a/tests/phpunit/unit/includes/Rest/Handler/ActionModuleBasedHandlerTestTrait.php
+++ b/tests/phpunit/unit/includes/Rest/Handler/ActionModuleBasedHandlerTestTrait.php
@@ -56,7 +56,7 @@ trait ActionModuleBasedHandlerTestTrait {
 
 		$module->method( 'execute' )
 			->willReturnCallback(
-				function () use ( $module, $resultData, $throwException ) {
+				static function () use ( $module, $resultData, $throwException ) {
 					if ( $throwException ) {
 						throw $throwException;
 					}
diff --git a/tests/phpunit/unit/includes/Rest/Handler/ContributionsCountHandlerTest.php b/tests/phpunit/unit/includes/Rest/Handler/ContributionsCountHandlerTest.php
index 98851d27f25..7363f22d8f7 100644
--- a/tests/phpunit/unit/includes/Rest/Handler/ContributionsCountHandlerTest.php
+++ b/tests/phpunit/unit/includes/Rest/Handler/ContributionsCountHandlerTest.php
@@ -31,7 +31,7 @@ class ContributionsCountHandlerTest extends \MediaWikiUnitTestCase {
 		);
 
 		$mockUserNameUtils->method( 'isIP' )
-			->willReturnCallback( function ( $name ) {
+			->willReturnCallback( static function ( $name ) {
 				return $name === '127.0.0.1';
 			} );
 
diff --git a/tests/phpunit/unit/includes/Rest/Handler/HandlerTest.php b/tests/phpunit/unit/includes/Rest/Handler/HandlerTest.php
index 2c68e2fcd2f..4967df0dd54 100644
--- a/tests/phpunit/unit/includes/Rest/Handler/HandlerTest.php
+++ b/tests/phpunit/unit/includes/Rest/Handler/HandlerTest.php
@@ -150,7 +150,7 @@ class HandlerTest extends \MediaWikiUnitTestCase {
 	public function testApplyConditionalResponseHeaders() {
 		$util = $this->createNoOpMock( ConditionalHeaderUtil::class, [ 'applyResponseHeaders' ] );
 		$util->method( 'applyResponseHeaders' )->willReturnCallback(
-			function ( ResponseInterface $response ) {
+			static function ( ResponseInterface $response ) {
 				$response->setHeader( 'Testing', 'foo' );
 			}
 		);
diff --git a/tests/phpunit/unit/includes/Rest/Handler/HandlerTestTrait.php b/tests/phpunit/unit/includes/Rest/Handler/HandlerTestTrait.php
index 84d37f38633..4a0cefa3f18 100644
--- a/tests/phpunit/unit/includes/Rest/Handler/HandlerTestTrait.php
+++ b/tests/phpunit/unit/includes/Rest/Handler/HandlerTestTrait.php
@@ -57,7 +57,7 @@ trait HandlerTestTrait {
 		Authority $authority = null
 	) {
 		$formatter = $this->createMock( ITextFormatter::class );
-		$formatter->method( 'format' )->willReturnCallback( function ( MessageValue $msg ) {
+		$formatter->method( 'format' )->willReturnCallback( static function ( MessageValue $msg ) {
 			return $msg->dump();
 		} );
 
@@ -66,7 +66,7 @@ trait HandlerTestTrait {
 
 		/** @var Router|MockObject $router */
 		$router = $this->createNoOpMock( Router::class, [ 'getRouteUrl' ] );
-		$router->method( 'getRouteUrl' )->willReturnCallback( function ( $route, $path = [], $query = [] ) {
+		$router->method( 'getRouteUrl' )->willReturnCallback( static function ( $route, $path = [], $query = [] ) {
 			foreach ( $path as $param => $value ) {
 				$route = str_replace( '{' . $param . '}', urlencode( $value ), $route );
 			}
diff --git a/tests/phpunit/unit/includes/Rest/Handler/MediaTestTrait.php b/tests/phpunit/unit/includes/Rest/Handler/MediaTestTrait.php
index e30769e4f0f..d55fc46ceaa 100644
--- a/tests/phpunit/unit/includes/Rest/Handler/MediaTestTrait.php
+++ b/tests/phpunit/unit/includes/Rest/Handler/MediaTestTrait.php
@@ -63,7 +63,7 @@ trait MediaTestTrait {
 		$file->method( 'getTitle' )->willReturn( $title );
 		$file->method( 'exists' )->willReturn( true );
 		$file->method( 'userCan' )->willReturn( true );
-		$file->method( 'getUser' )->willReturnCallback( function ( $type ) {
+		$file->method( 'getUser' )->willReturnCallback( static function ( $type ) {
 			return $type === 'id' ? 7 : 'Alice';
 		} );
 		$file->method( 'getTimestamp' )->willReturn( '20200102030405' );
@@ -111,7 +111,7 @@ trait MediaTestTrait {
 			}
 		};
 
-		$findFiles = function ( array $inputItems ) use ( $findFile ) {
+		$findFiles = static function ( array $inputItems ) use ( $findFile ) {
 			$files = [];
 			foreach ( $inputItems as $item ) {
 				$files[] = ( $findFile )( $item['title'] );
diff --git a/tests/phpunit/unit/includes/Rest/Handler/SearchHandlerTest.php b/tests/phpunit/unit/includes/Rest/Handler/SearchHandlerTest.php
index 62096a73395..4b464d5c37a 100644
--- a/tests/phpunit/unit/includes/Rest/Handler/SearchHandlerTest.php
+++ b/tests/phpunit/unit/includes/Rest/Handler/SearchHandlerTest.php
@@ -156,7 +156,7 @@ class SearchHandlerTest extends \MediaWikiUnitTestCase {
 		$handler = $this->newHandler( $query, $titleResults, $textResults );
 		$config = [ 'mode' => SearchHandler::FULLTEXT_MODE ];
 		$data = $this->executeHandlerAndGetBodyData( $handler, $request, $config, [], [], [],
-			$this->mockAnonAuthority( function ( string $permission, ?PageIdentity $target ) {
+			$this->mockAnonAuthority( static function ( string $permission, ?PageIdentity $target ) {
 				return $target && !preg_match( '/Forbidden/', $target->getDBkey() );
 			} ) );
 
@@ -381,13 +381,13 @@ class SearchHandlerTest extends \MediaWikiUnitTestCase {
 
 		$data = $this->executeHandlerAndGetBodyData( $handler, $request, [], [
 			'SearchResultProvideDescription' =>
-				function ( array $pageIdentities, array &$result ) {
+				static function ( array $pageIdentities, array &$result ) {
 					foreach ( $pageIdentities as $pageId => $pageIdentity ) {
 						$result[ $pageId ] = 'Description_' . $pageIdentity->getId();
 					}
 				},
 			'SearchResultProvideThumbnail' =>
-				function ( array $pageIdentities, array &$result ) {
+				static function ( array $pageIdentities, array &$result ) {
 					foreach ( $pageIdentities as $pageId => $pageIdentity ) {
 						$result[ $pageId ] = new SearchResultThumbnail(
 							'image/png',
diff --git a/tests/phpunit/unit/includes/Rest/Handler/UserContributionsHandlerTest.php b/tests/phpunit/unit/includes/Rest/Handler/UserContributionsHandlerTest.php
index 3bdc10b9e06..6a7ce2732d8 100644
--- a/tests/phpunit/unit/includes/Rest/Handler/UserContributionsHandlerTest.php
+++ b/tests/phpunit/unit/includes/Rest/Handler/UserContributionsHandlerTest.php
@@ -134,7 +134,7 @@ class UserContributionsHandlerTest extends \MediaWikiUnitTestCase {
 		);
 
 		$mockUserNameUtils->method( 'isIP' )
-			->willReturnCallback( function ( $name ) {
+			->willReturnCallback( static function ( $name ) {
 				return $name === '127.0.0.1';
 			} );
 
diff --git a/tests/phpunit/unit/includes/cache/HtmlCacheUpdaterTest.php b/tests/phpunit/unit/includes/cache/HtmlCacheUpdaterTest.php
index 8ffcaab5448..8a964e55da9 100644
--- a/tests/phpunit/unit/includes/cache/HtmlCacheUpdaterTest.php
+++ b/tests/phpunit/unit/includes/cache/HtmlCacheUpdaterTest.php
@@ -11,7 +11,7 @@ class HtmlCacheUpdaterTest extends MediaWikiUnitTestCase {
 			$this->createHookContainer(),
 			0, false, 86400 );
 		$title = $this->createMock( Title::class );
-		$title->method( 'getInternalURL' )->will( $this->returnCallback( function ( $query = '' ) {
+		$title->method( 'getInternalURL' )->will( $this->returnCallback( static function ( $query = '' ) {
 			return 'https://test/?title=Example' . ( $query !== '' ? "&$query" : '' );
 		} ) );
 
@@ -32,7 +32,7 @@ class HtmlCacheUpdaterTest extends MediaWikiUnitTestCase {
 		);
 
 		$title = $this->createMock( Title::class );
-		$title->method( 'getInternalURL' )->will( $this->returnCallback( function ( $query = '' ) {
+		$title->method( 'getInternalURL' )->will( $this->returnCallback( static function ( $query = '' ) {
 			return 'https://test/?title=User:Example/foo.js' . ( $query !== '' ? "&$query" : '' );
 		} ) );
 		$title->method( 'isUserJsConfigPage' )->willReturn( true );
@@ -47,7 +47,7 @@ class HtmlCacheUpdaterTest extends MediaWikiUnitTestCase {
 		);
 
 		$title = $this->createMock( Title::class );
-		$title->method( 'getInternalURL' )->will( $this->returnCallback( function ( $query = '' ) {
+		$title->method( 'getInternalURL' )->will( $this->returnCallback( static function ( $query = '' ) {
 			return 'https://test/?title=MediaWiki:Example.js' . ( $query !== '' ? "&$query" : '' );
 		} ) );
 		$title->method( 'isSiteJsConfigPage' )->willReturn( true );
diff --git a/tests/phpunit/unit/includes/content/ContentHandlerFactoryTest.php b/tests/phpunit/unit/includes/content/ContentHandlerFactoryTest.php
index de637f26bbe..100f9740bb3 100644
--- a/tests/phpunit/unit/includes/content/ContentHandlerFactoryTest.php
+++ b/tests/phpunit/unit/includes/content/ContentHandlerFactoryTest.php
@@ -16,7 +16,7 @@ class ContentHandlerFactoryTest extends MediaWikiUnitTestCase {
 	protected function setUp() : void {
 		parent::setUp();
 
-		$this->logger = new TestLogger( false, function ( $message, $level ) {
+		$this->logger = new TestLogger( false, static function ( $message, $level ) {
 			return $level === LogLevel::INFO ? null : $message;
 		} );
 	}
@@ -26,7 +26,7 @@ class ContentHandlerFactoryTest extends MediaWikiUnitTestCase {
 			'typical list' => [
 				[
 					'ExistClassName' => DummyContentHandlerForTesting::class,
-					'ExistCallbackWithExistClassName' => function ( $modelID ) {
+					'ExistCallbackWithExistClassName' => static function ( $modelID ) {
 						return new DummyContentHandlerForTesting( $modelID );
 					},
 				],
@@ -102,7 +102,7 @@ class ContentHandlerFactoryTest extends MediaWikiUnitTestCase {
 			$this->assertFalse( $factory->isDefinedModel( $modelID ) );
 			$contentHandler = null;
 			$hookContainer->register( 'ContentHandlerForModelID',
-				function ( $handlerSpec, &$contentHandler ) use (
+				static function ( $handlerSpec, &$contentHandler ) use (
 					$contentHandlerExpected
 				) {
 					$contentHandler = $contentHandlerExpected;
@@ -120,13 +120,13 @@ class ContentHandlerFactoryTest extends MediaWikiUnitTestCase {
 		return [
 			'MWException expected' => [
 				[
-					'ExistCallbackWithWrongType' => function () {
+					'ExistCallbackWithWrongType' => static function () {
 						return true;
 					},
-					'ExistCallbackWithNull' => function () {
+					'ExistCallbackWithNull' => static function () {
 						return null;
 					},
-					'ExistCallbackWithEmptyString' => function () {
+					'ExistCallbackWithEmptyString' => static function () {
 						return '';
 					},
 					'WrongClassName' => self::class,
@@ -139,7 +139,7 @@ class ContentHandlerFactoryTest extends MediaWikiUnitTestCase {
 			'Error expected' => [
 				[
 					'WrongClassNameNotExist' => 'ClassNameNotExist',
-					'ExistCallbackWithNotExistClassName' => function () {
+					'ExistCallbackWithNotExistClassName' => static function () {
 						return ClassNameNotExist();
 					},
 					'EmptyString' => '',
@@ -264,7 +264,7 @@ class ContentHandlerFactoryTest extends MediaWikiUnitTestCase {
 		);
 
 		$hookContainer->register( 'GetContentModels',
-			function ( &$models ) use ( $name4 ) {
+			static function ( &$models ) use ( $name4 ) {
 				$models[] = $name4;
 			} );
 		$this->assertArrayEquals(
@@ -312,7 +312,7 @@ class ContentHandlerFactoryTest extends MediaWikiUnitTestCase {
 
 		$hookContainer->register(
 			'GetContentModels',
-			function ( &$models ) use ( $name4 ) {
+			static function ( &$models ) use ( $name4 ) {
 				$models[] = $name4;
 			} );
 
diff --git a/tests/phpunit/unit/includes/debug/DeprecatablePropertyArrayTest.php b/tests/phpunit/unit/includes/debug/DeprecatablePropertyArrayTest.php
index 32866d171b3..84ccb45d900 100644
--- a/tests/phpunit/unit/includes/debug/DeprecatablePropertyArrayTest.php
+++ b/tests/phpunit/unit/includes/debug/DeprecatablePropertyArrayTest.php
@@ -23,7 +23,7 @@ class DeprecatablePropertyArrayTest extends MediaWikiUnitTestCase {
 		$array = new DeprecatablePropertyArray(
 			[
 				self::PROP_NAME => 'test_value',
-				'callback' => function () {
+				'callback' => static function () {
 					return 'callback_test_value';
 				},
 			],
diff --git a/tests/phpunit/unit/includes/deferred/MWCallableUpdateTest.php b/tests/phpunit/unit/includes/deferred/MWCallableUpdateTest.php
index 20ffddb491b..f3e4fc39e1b 100644
--- a/tests/phpunit/unit/includes/deferred/MWCallableUpdateTest.php
+++ b/tests/phpunit/unit/includes/deferred/MWCallableUpdateTest.php
@@ -7,7 +7,7 @@ class MWCallableUpdateTest extends MediaWikiUnitTestCase {
 
 	public function testDoUpdate() {
 		$ran = 0;
-		$update = new MWCallableUpdate( function () use ( &$ran ) {
+		$update = new MWCallableUpdate( static function () use ( &$ran ) {
 			$ran++;
 		} );
 		$this->assertSame( 0, $ran );
@@ -20,7 +20,7 @@ class MWCallableUpdateTest extends MediaWikiUnitTestCase {
 		$db = new DatabaseTestHelper( __METHOD__ );
 		$db->begin( __METHOD__ );
 		$ran = 0;
-		$update = new MWCallableUpdate( function () use ( &$ran ) {
+		$update = new MWCallableUpdate( static function () use ( &$ran ) {
 			$ran++;
 		}, __METHOD__, $db );
 
@@ -40,7 +40,7 @@ class MWCallableUpdateTest extends MediaWikiUnitTestCase {
 		$db2 = new DatabaseTestHelper( __METHOD__ );
 		$db2->begin( __METHOD__ );
 		$ran = 0;
-		$update = new MWCallableUpdate( function () use ( &$ran ) {
+		$update = new MWCallableUpdate( static function () use ( &$ran ) {
 			$ran++;
 		}, __METHOD__, [ $db1, $db2 ] );
 
@@ -63,7 +63,7 @@ class MWCallableUpdateTest extends MediaWikiUnitTestCase {
 		$db2 = new DatabaseTestHelper( __METHOD__ );
 		$db2->begin( __METHOD__ );
 		$ran = 0;
-		$update = new MWCallableUpdate( function () use ( &$ran ) {
+		$update = new MWCallableUpdate( static function () use ( &$ran ) {
 			$ran++;
 		}, __METHOD__, [ $db1, $db2 ] );
 
diff --git a/tests/phpunit/unit/includes/deferred/TransactionRoundDefiningUpdateTest.php b/tests/phpunit/unit/includes/deferred/TransactionRoundDefiningUpdateTest.php
index c16c3974023..2e4c09c44ad 100644
--- a/tests/phpunit/unit/includes/deferred/TransactionRoundDefiningUpdateTest.php
+++ b/tests/phpunit/unit/includes/deferred/TransactionRoundDefiningUpdateTest.php
@@ -7,7 +7,7 @@ class TransactionRoundDefiningUpdateTest extends MediaWikiUnitTestCase {
 
 	public function testDoUpdate() {
 		$ran = 0;
-		$update = new TransactionRoundDefiningUpdate( function () use ( &$ran ) {
+		$update = new TransactionRoundDefiningUpdate( static function () use ( &$ran ) {
 			$ran++;
 		} );
 		$this->assertSame( 0, $ran );
diff --git a/tests/phpunit/unit/includes/diff/ArrayDiffFormatterTest.php b/tests/phpunit/unit/includes/diff/ArrayDiffFormatterTest.php
index e9992026db0..45d9afc0a4a 100644
--- a/tests/phpunit/unit/includes/diff/ArrayDiffFormatterTest.php
+++ b/tests/phpunit/unit/includes/diff/ArrayDiffFormatterTest.php
@@ -43,7 +43,7 @@ class ArrayDiffFormatterTest extends \MediaWikiUnitTestCase {
 			$diffOp->expects( $this->any() )
 				->method( 'getClosing' )
 				->with( $this->isType( 'integer' ) )
-				->will( $this->returnCallback( function () {
+				->will( $this->returnCallback( static function () {
 					return 'mockLine';
 				} ) );
 		} else {
diff --git a/tests/phpunit/unit/includes/filebackend/FileBackendGroupTestTrait.php b/tests/phpunit/unit/includes/filebackend/FileBackendGroupTestTrait.php
index 4784cb960f9..6a1075adb12 100644
--- a/tests/phpunit/unit/includes/filebackend/FileBackendGroupTestTrait.php
+++ b/tests/phpunit/unit/includes/filebackend/FileBackendGroupTestTrait.php
@@ -330,7 +330,7 @@ trait FileBackendGroupTestTrait {
 			'class' => '',
 			'lockManager' => 'fsLockManager',
 			'fileJournal' => [ 'factory' =>
-				function () use ( $mockJournal ) {
+				static function () use ( $mockJournal ) {
 					return $mockJournal;
 				}
 			],
diff --git a/tests/phpunit/unit/includes/filebackend/lockmanager/MySqlLockManagerTest.php b/tests/phpunit/unit/includes/filebackend/lockmanager/MySqlLockManagerTest.php
index e030fe0557d..db2e4e903ec 100644
--- a/tests/phpunit/unit/includes/filebackend/lockmanager/MySqlLockManagerTest.php
+++ b/tests/phpunit/unit/includes/filebackend/lockmanager/MySqlLockManagerTest.php
@@ -39,12 +39,12 @@ class MySqlLockManagerTest extends MediaWikiUnitTestCase {
 
 		$mockDb->expects( $this->once() )->method( 'query' )
 			->with( 'SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;' )
-			->will( $this->returnCallback( function () use ( &$isolationSet ) {
+			->will( $this->returnCallback( static function () use ( &$isolationSet ) {
 				$isolationSet = true;
 			} ) );
 
 		$mockDb->expects( $this->once() )->method( 'startAtomic' )
-			->will( $this->returnCallback( function () use ( &$trxStarted ) {
+			->will( $this->returnCallback( static function () use ( &$trxStarted ) {
 				$trxStarted = true;
 			} ) );
 
@@ -114,7 +114,7 @@ class MySqlLockManagerTest extends MediaWikiUnitTestCase {
 			->withConsecutive( ...$expectedSelectFieldArgs )
 			->willReturnOnConsecutiveCalls( ...$selectFieldReturns );
 
-		$mockDb->method( 'addQuotes' )->will( $this->returnCallback( function ( $s ) {
+		$mockDb->method( 'addQuotes' )->will( $this->returnCallback( static function ( $s ) {
 			return "'$s'";
 		} ) );
 
diff --git a/tests/phpunit/unit/includes/htmlform/HTMLCheckMatrixTest.php b/tests/phpunit/unit/includes/htmlform/HTMLCheckMatrixTest.php
index d26fa35fff9..fa5ea982774 100644
--- a/tests/phpunit/unit/includes/htmlform/HTMLCheckMatrixTest.php
+++ b/tests/phpunit/unit/includes/htmlform/HTMLCheckMatrixTest.php
@@ -29,7 +29,7 @@ class HTMLCheckMatrixTest extends MediaWikiUnitTestCase {
 	public function testValidateCallsUserDefinedValidationCallback() {
 		$called = false;
 		$field = new HTMLCheckMatrix( self::$defaultOptions + [
-			'validation-callback' => function () use ( &$called ) {
+			'validation-callback' => static function () use ( &$called ) {
 				$called = true;
 
 				return false;
diff --git a/tests/phpunit/unit/includes/language/LanguageFallbackTest.php b/tests/phpunit/unit/includes/language/LanguageFallbackTest.php
index b8f33cd0e9d..406c6c94134 100644
--- a/tests/phpunit/unit/includes/language/LanguageFallbackTest.php
+++ b/tests/phpunit/unit/includes/language/LanguageFallbackTest.php
@@ -22,7 +22,7 @@ class LanguageFallbackTest extends MediaWikiUnitTestCase {
 	private function getLanguageNameUtils() {
 		$mockLangNameUtils = $this->createMock( LanguageNameUtils::class );
 		$mockLangNameUtils->method( 'isValidBuiltInCode' )
-			->will( $this->returnCallback( function ( $code ) {
+			->will( $this->returnCallback( static function ( $code ) {
 				// One-line copy-paste
 				return (bool)preg_match( '/^[a-z0-9-]{2,}$/', $code );
 			} ) );
diff --git a/tests/phpunit/unit/includes/language/LanguageFallbackTestTrait.php b/tests/phpunit/unit/includes/language/LanguageFallbackTestTrait.php
index 19c6bd9f1a3..86a506ba3e4 100644
--- a/tests/phpunit/unit/includes/language/LanguageFallbackTestTrait.php
+++ b/tests/phpunit/unit/includes/language/LanguageFallbackTestTrait.php
@@ -42,7 +42,7 @@ trait LanguageFallbackTestTrait {
 		$mockLocCache->expects( $this->exactly( $expectedGets ) )->method( 'getItem' )
 			->with( $this->anything(),
 				$this->logicalOr( 'fallbackSequence', 'originalFallbackSequence' ) )
-			->will( $this->returnCallback( function ( $code, $key ) use ( $map ) {
+			->will( $this->returnCallback( static function ( $code, $key ) use ( $map ) {
 				if ( $key === 'originalFallbackSequence' || $code === 'en' ) {
 					return $map[$code];
 				}
diff --git a/tests/phpunit/unit/includes/language/LanguageNameUtilsTestTrait.php b/tests/phpunit/unit/includes/language/LanguageNameUtilsTestTrait.php
index f760c37505e..0780b30c7fa 100644
--- a/tests/phpunit/unit/includes/language/LanguageNameUtilsTestTrait.php
+++ b/tests/phpunit/unit/includes/language/LanguageNameUtilsTestTrait.php
@@ -202,7 +202,7 @@ trait LanguageNameUtilsTestTrait {
 	 */
 	public function testGetLanguageNames_withHook( $expected, $code, ...$otherArgs ) {
 		$this->setLanguageTemporaryHook( 'LanguageGetTranslatedLanguageNames',
-			function ( &$names, $inLanguage ) {
+			static function ( &$names, $inLanguage ) {
 				switch ( $inLanguage ) {
 					case 'de':
 						$names = [
@@ -262,7 +262,7 @@ trait LanguageNameUtilsTestTrait {
 	 */
 	public function testGetLanguageNames_ExtraLanguageNames( $expected, $code, ...$otherArgs ) {
 		$this->setLanguageTemporaryHook( 'LanguageGetTranslatedLanguageNames',
-			function ( &$names ) {
+			static function ( &$names ) {
 				$names['de'] = 'die deutsche Sprache';
 			}
 		);
@@ -296,7 +296,7 @@ trait LanguageNameUtilsTestTrait {
 	 */
 	public function testGetLanguageNames_parameterDefault() {
 		$this->setLanguageTemporaryHook( 'LanguageGetTranslatedLanguageNames',
-			function ( &$names ) {
+			static function ( &$names ) {
 				$names = [ 'sqsqsqsq' => '!!?!' ];
 			}
 		);
@@ -342,7 +342,7 @@ trait LanguageNameUtilsTestTrait {
 	public function testGetLanguageNames_hookNotCalledForAutonyms() {
 		$count = 0;
 		$this->setLanguageTemporaryHook( 'LanguageGetTranslatedLanguageNames',
-			function () use ( &$count ) {
+			static function () use ( &$count ) {
 				$count++;
 			}
 		);
@@ -366,7 +366,7 @@ trait LanguageNameUtilsTestTrait {
 	 */
 	public function testGetLanguageNames_pigLatin( $expected, ...$otherArgs ) {
 		$this->setLanguageTemporaryHook( 'LanguageGetTranslatedLanguageNames',
-			function ( &$names, $inLanguage ) {
+			static function ( &$names, $inLanguage ) {
 				switch ( $inLanguage ) {
 					case 'fr':
 						$names = [ 'en-x-piglatin' => 'latin de cochons' ];
diff --git a/tests/phpunit/unit/includes/libs/MemoizedCallableTest.php b/tests/phpunit/unit/includes/libs/MemoizedCallableTest.php
index cc707f28a30..1ad4d06bf37 100644
--- a/tests/phpunit/unit/includes/libs/MemoizedCallableTest.php
+++ b/tests/phpunit/unit/includes/libs/MemoizedCallableTest.php
@@ -83,11 +83,11 @@ class MemoizedCallableTest extends PHPUnit\Framework\TestCase {
 	 * Closure names should be distinct.
 	 */
 	public function testMemoizedClosure() {
-		$a = new MemoizedCallable( function () {
+		$a = new MemoizedCallable( static function () {
 			return 'a';
 		} );
 
-		$b = new MemoizedCallable( function () {
+		$b = new MemoizedCallable( static function () {
 			return 'b';
 		} );
 
@@ -102,7 +102,7 @@ class MemoizedCallableTest extends PHPUnit\Framework\TestCase {
 			$b->callableName
 		);
 
-		$c = new ArrayBackedMemoizedCallable( function () {
+		$c = new ArrayBackedMemoizedCallable( static function () {
 			return rand();
 		} );
 		$this->assertEquals( $c->invokeArgs(), $c->invokeArgs(), 'memoized random' );
diff --git a/tests/phpunit/unit/includes/libs/XmlTypeCheckTest.php b/tests/phpunit/unit/includes/libs/XmlTypeCheckTest.php
index 6e1ba4b3784..079f24a4f80 100644
--- a/tests/phpunit/unit/includes/libs/XmlTypeCheckTest.php
+++ b/tests/phpunit/unit/includes/libs/XmlTypeCheckTest.php
@@ -68,7 +68,7 @@ XML;
 			null,
 			false,
 			[
-				'processing_instruction_handler' => function () use ( &$called ) {
+				'processing_instruction_handler' => static function () use ( &$called ) {
 					$called = true;
 				}
 			]
diff --git a/tests/phpunit/unit/includes/libs/filebackend/FileBackendTest.php b/tests/phpunit/unit/includes/libs/filebackend/FileBackendTest.php
index 0624000b771..0be0250c464 100644
--- a/tests/phpunit/unit/includes/libs/filebackend/FileBackendTest.php
+++ b/tests/phpunit/unit/includes/libs/filebackend/FileBackendTest.php
@@ -247,11 +247,11 @@ class FileBackendTest extends MediaWikiUnitTestCase {
 			'obResetFunc default value' => [ 'obResetFunc',
 				// I'd've thought the return type should be 'callable', but apparently protected
 				// methods aren't callable.
-				function ( FileBackend $backend ) : array {
+				static function ( FileBackend $backend ) : array {
 					return [ $backend, 'resetOutputBuffer' ];
 				} ],
 			'obResetFunc null' => [ 'obResetFunc',
-				function ( FileBackend $backend ) : array {
+				static function ( FileBackend $backend ) : array {
 					return [ $backend, 'resetOutputBuffer' ];
 				} ],
 			'obResetFunc set' => [ 'obResetFunc', 'wfSomeImaginaryFunction',
diff --git a/tests/phpunit/unit/includes/libs/objectcache/WANObjectCacheTest.php b/tests/phpunit/unit/includes/libs/objectcache/WANObjectCacheTest.php
index 66eb0b70935..f66463065b0 100644
--- a/tests/phpunit/unit/includes/libs/objectcache/WANObjectCacheTest.php
+++ b/tests/phpunit/unit/includes/libs/objectcache/WANObjectCacheTest.php
@@ -178,7 +178,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$key = "mykey-" . wfRandomString();
 
 		$hits = 0;
-		$callback = function ( $oldValue, &$ttl, &$setOpts ) use ( &$hits ) {
+		$callback = static function ( $oldValue, &$ttl, &$setOpts ) use ( &$hits ) {
 			++$hits;
 			return 42;
 		};
@@ -202,7 +202,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$cache->setMockTime( $mockWallClock );
 
 		$hit = 0;
-		$fn = function () use ( &$hit ) {
+		$fn = static function () use ( &$hit ) {
 			++$hit;
 			return 42;
 		};
@@ -247,7 +247,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$cache->setMockTime( $mockWallClock );
 
 		$hit = 0;
-		$fn = function () use ( &$hit ) {
+		$fn = static function () use ( &$hit ) {
 			++$hit;
 			return 42;
 		};
@@ -293,7 +293,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		};
 
 		$outerHit = 0;
-		$outerFn = function () use ( $keyInner, $innerFn, $cache, &$outerHit ) {
+		$outerFn = static function () use ( $keyInner, $innerFn, $cache, &$outerHit ) {
 			++$outerHit;
 			$v = $cache->getWithSetCallback( $keyInner, 100, $innerFn, [ 'pcTTL' => 5 ] );
 
@@ -353,7 +353,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$priorValue = null;
 		$priorAsOf = null;
 		$wasSet = 0;
-		$func = function ( $old, &$ttl, &$opts, $asOf )
+		$func = static function ( $old, &$ttl, &$opts, $asOf )
 		use ( &$wasSet, &$priorValue, &$priorAsOf, $value ) {
 			++$wasSet;
 			$priorValue = $old;
@@ -428,7 +428,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 
 		$oldValReceived = -1;
 		$oldAsOfReceived = -1;
-		$checkFunc = function ( $oldVal, &$ttl, array $setOpts, $oldAsOf )
+		$checkFunc = static function ( $oldVal, &$ttl, array $setOpts, $oldAsOf )
 		use ( &$oldValReceived, &$oldAsOfReceived, &$wasSet ) {
 			++$wasSet;
 			$oldValReceived = $oldVal;
@@ -537,7 +537,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$mockWallClock = 1549343530.2053;
 		$cache->setMockTime( $mockWallClock );
 
-		$checkFunc = function ( $oldVal, &$ttl, array $setOpts, $oldAsOf )
+		$checkFunc = static function ( $oldVal, &$ttl, array $setOpts, $oldAsOf )
 		use ( &$wasSet ) {
 			++$wasSet;
 
@@ -593,7 +593,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 	public function testPreemtiveRefresh() {
 		$value = 'KatCafe';
 		$wasSet = 0;
-		$func = function ( $old, &$ttl, &$opts, $asOf ) use ( &$wasSet, &$value )
+		$func = static function ( $old, &$ttl, &$opts, $asOf ) use ( &$wasSet, &$value )
 		{
 			++$wasSet;
 			return $value;
@@ -807,7 +807,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 
 		$calls = 0;
 		$ids = [ 1, 2, 3, 4, 5, 6 ];
-		$keyFunc = function ( $id, WANObjectCache $wanCache ) {
+		$keyFunc = static function ( $id, WANObjectCache $wanCache ) {
 			return $wanCache->makeKey( 'test', $id );
 		};
 		$keyedIds = $cache->makeMultiKeys( $ids, $keyFunc );
@@ -876,7 +876,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 			->setConstructorArgs( [
 				[
 					'cache' => $bag,
-					'asyncHandler' => function ( $callback ) use ( &$deferredCbs ) {
+					'asyncHandler' => static function ( $callback ) use ( &$deferredCbs ) {
 						$deferredCbs[] = $callback;
 					}
 				]
@@ -888,7 +888,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 
 		$wasSet = 0;
 		$keyedIds = new ArrayIterator( $idsByKey );
-		$genFunc = function ( $id, $old, &$ttl, &$opts, $asOf ) use ( &$wasSet ) {
+		$genFunc = static function ( $id, $old, &$ttl, &$opts, $asOf ) use ( &$wasSet ) {
 			++$wasSet;
 			$ttl = 20; // override with another value
 			return "@$id$";
@@ -1059,7 +1059,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 
 		$calls = 0;
 		$ids = [ 1, 2, 3, 4, 5, 6 ];
-		$keyFunc = function ( $id, WANObjectCache $wanCache ) {
+		$keyFunc = static function ( $id, WANObjectCache $wanCache ) {
 			return $wanCache->makeKey( 'test', $id );
 		};
 		$keyedIds = $cache->makeMultiKeys( $ids, $keyFunc );
@@ -1120,7 +1120,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 			->setConstructorArgs( [
 				[
 					'cache' => $bag,
-					'asyncHandler' => function ( $callback ) use ( &$deferredCbs ) {
+					'asyncHandler' => static function ( $callback ) use ( &$deferredCbs ) {
 						$deferredCbs[] = $callback;
 					}
 				]
@@ -1132,7 +1132,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 
 		$wasSet = 0;
 		$keyedIds = new ArrayIterator( $idsByKey );
-		$genFunc = function ( array $ids, array &$ttls, array &$setOpts ) use ( &$wasSet ) {
+		$genFunc = static function ( array $ids, array &$ttls, array &$setOpts ) use ( &$wasSet ) {
 			$newValues = [];
 			foreach ( $ids as $id ) {
 				++$wasSet;
@@ -1210,7 +1210,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$cache->setMockTime( $mockWallClock );
 
 		$calls = 0;
-		$func = function () use ( &$calls, $value, $cache, $key ) {
+		$func = static function () use ( &$calls, $value, $cache, $key ) {
 			++$calls;
 			return $value;
 		};
@@ -1278,7 +1278,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$cache->setMockTime( $mockWallClock );
 
 		$calls = 0;
-		$func = function ( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value, &$mockWallClock ) {
+		$func = static function ( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value, &$mockWallClock ) {
 			++$calls;
 			$setOpts['since'] = $mockWallClock;
 			$mockWallClock += 10;
@@ -1320,7 +1320,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$this->assertSame( 3, $calls, 'Callback was used (mutex not acquired, not in cache)' );
 
 		$calls = 0;
-		$func2 = function ( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value ) {
+		$func2 = static function ( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value ) {
 			++$calls;
 			$setOpts['lag'] = 15;
 			return $value;
@@ -1360,7 +1360,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$cache->setMockTime( $mockWallClock );
 
 		$calls = 0;
-		$func = function () use ( &$calls, $value ) {
+		$func = static function () use ( &$calls, $value ) {
 			++$calls;
 			return $value;
 		};
@@ -1411,7 +1411,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 
 		return [
 			[
-				function () {
+				static function () {
 					return "Saint Oliver Plunckett";
 				},
 				'Saint Oliver Plunckett'
@@ -1437,7 +1437,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$cache->setMockTime( $mockWallClock );
 
 		$calls = 0;
-		$func = function () use ( &$calls ) {
+		$func = static function () use ( &$calls ) {
 			++$calls;
 			return 418;
 		};
@@ -1715,7 +1715,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$valueV2 = [ wfRandomString() ];
 
 		$wasSet = 0;
-		$funcV1 = function () use ( &$wasSet, $valueV1 ) {
+		$funcV1 = static function () use ( &$wasSet, $valueV1 ) {
 			++$wasSet;
 
 			return $valueV1;
@@ -1723,7 +1723,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 
 		$priorValue = false;
 		$priorAsOf = null;
-		$funcV2 = function ( $oldValue, &$ttl, $setOpts, $oldAsOf )
+		$funcV2 = static function ( $oldValue, &$ttl, $setOpts, $oldAsOf )
 		use ( &$wasSet, $valueV2, &$priorValue, &$priorAsOf ) {
 			$priorValue = $oldValue;
 			$priorAsOf = $oldAsOf;
@@ -1796,7 +1796,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 
 		$value = 'CRL-40-940';
 		$wasCalled = 0;
-		$func = function () use ( &$wasCalled, $value ) {
+		$func = static function () use ( &$wasCalled, $value ) {
 			$wasCalled++;
 
 			return $value;
@@ -2071,7 +2071,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 			'region' => 'pmtpa',
 			'cluster' => 'mw-wan'
 		] );
-		$valFunc = function () {
+		$valFunc = static function () {
 			return 1;
 		};
 
@@ -2344,7 +2344,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 	public function testMakeMultiKeysIntString() {
 		list( $cache ) = $this->newWanCache();
 		$ids = [ 1, 2, 3, 4, '4', 5, 6, 6, 7, '7' ];
-		$keyCallback = function ( $id, WANObjectCache $cache ) {
+		$keyCallback = static function ( $id, WANObjectCache $cache ) {
 			return $cache->makeGlobalKey( 'key', $id, 'a', $id, 'b' );
 		};
 
@@ -2372,7 +2372,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 		$this->expectException( UnexpectedValueException::class );
 		$cache->makeMultiKeys(
 			$ids,
-			function ( $id ) {
+			static function ( $id ) {
 				return "keymod:" . $id % 3;
 			}
 		);
@@ -2441,7 +2441,7 @@ class WANObjectCacheTest extends PHPUnit\Framework\TestCase {
 	public function testCoalesceKeys( array $params, $keyNeedle ) {
 		list( $cache, $bag ) = $this->newWanCache( $params );
 		$key = wfRandomString();
-		$callback = function () {
+		$callback = static function () {
 			return 2020;
 		};
 
diff --git a/tests/phpunit/unit/includes/libs/rdbms/database/DBConnRefTest.php b/tests/phpunit/unit/includes/libs/rdbms/database/DBConnRefTest.php
index 096edc5fa03..a464abd29c1 100644
--- a/tests/phpunit/unit/includes/libs/rdbms/database/DBConnRefTest.php
+++ b/tests/phpunit/unit/includes/libs/rdbms/database/DBConnRefTest.php
@@ -43,19 +43,19 @@ class DBConnRefTest extends PHPUnit\Framework\TestCase {
 			->getMock();
 
 		$open = true;
-		$db->method( 'select' )->willReturnCallback( function () use ( &$open ) {
+		$db->method( 'select' )->willReturnCallback( static function () use ( &$open ) {
 			if ( !$open ) {
 				throw new LogicException( "Not open" );
 			}
 
 			return new FakeResultWrapper( [] );
 		} );
-		$db->method( 'close' )->willReturnCallback( function () use ( &$open ) {
+		$db->method( 'close' )->willReturnCallback( static function () use ( &$open ) {
 			$open = false;
 
 			return true;
 		} );
-		$db->method( 'isOpen' )->willReturnCallback( function () use ( &$open ) {
+		$db->method( 'isOpen' )->willReturnCallback( static function () use ( &$open ) {
 			return $open;
 		} );
 
diff --git a/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseMysqlBaseTest.php b/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseMysqlBaseTest.php
index 1d494e025dd..72262cc1f6f 100644
--- a/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseMysqlBaseTest.php
+++ b/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseMysqlBaseTest.php
@@ -431,7 +431,7 @@ class DatabaseMysqlBaseTest extends PHPUnit\Framework\TestCase {
 		$db->method( 'useGTIDs' )->willReturn( true );
 		$db->method( 'getServerGTIDs' )->willReturn( $gtable );
 		$db->method( 'getServerRoleStatus' )->willReturnCallback(
-			function ( $role ) use ( $rBLtable, $mBLtable ) {
+			static function ( $role ) use ( $rBLtable, $mBLtable ) {
 				if ( $role === 'SLAVE' ) {
 					return $rBLtable;
 				} elseif ( $role === 'MASTER' ) {
@@ -697,7 +697,7 @@ class DatabaseMysqlBaseTest extends PHPUnit\Framework\TestCase {
 			->setMethods( [ 'mysqlRealEscapeString', 'dbSchema', 'tablePrefix' ] )
 			->getMock();
 		$db->method( 'mysqlRealEscapeString' )->willReturnCallback(
-			function ( $s ) {
+			static function ( $s ) {
 				return str_replace( "'", "\\'", $s );
 			}
 		);
@@ -731,7 +731,7 @@ class DatabaseMysqlBaseTest extends PHPUnit\Framework\TestCase {
 			->setMethods( [ 'mysqlRealEscapeString', 'dbSchema', 'tablePrefix' ] )
 			->getMock();
 		$db->method( 'mysqlRealEscapeString' )->willReturnCallback(
-			function ( $s ) {
+			static function ( $s ) {
 				return str_replace( "'", "\\'", $s );
 			}
 		);
diff --git a/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseSQLTest.php b/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseSQLTest.php
index 921d9384c06..b86b084a1cf 100644
--- a/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseSQLTest.php
+++ b/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseSQLTest.php
@@ -1913,7 +1913,7 @@ class DatabaseSQLTest extends PHPUnit\Framework\TestCase {
 		try {
 			$this->database->doAtomicSection(
 				__METHOD__,
-				function () {
+				static function () {
 					throw new RuntimeException( 'Test exception' );
 				}
 			);
diff --git a/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseSqliteRdbmsTest.php b/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseSqliteRdbmsTest.php
index b58853611be..e6186d03323 100644
--- a/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseSqliteRdbmsTest.php
+++ b/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseSqliteRdbmsTest.php
@@ -23,7 +23,7 @@ class DatabaseSqliteRdbmsTest extends PHPUnit\Framework\TestCase {
 			->getMock();
 
 		$db->expects( $this->any() )->method( 'addQuotes' )->willReturnCallback(
-			function ( $s ) {
+			static function ( $s ) {
 				return "'$s'";
 			}
 		);
diff --git a/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseTest.php b/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseTest.php
index 2e24f4fa956..e70b7972116 100644
--- a/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseTest.php
+++ b/tests/phpunit/unit/includes/libs/rdbms/database/DatabaseTest.php
@@ -185,7 +185,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 		$db->clearFlag( DBO_TRX );
 		$called = false;
 		$flagSet = null;
-		$callback = function ( $trigger, IDatabase $db ) use ( &$flagSet, &$called ) {
+		$callback = static function ( $trigger, IDatabase $db ) use ( &$flagSet, &$called ) {
 			$called = true;
 			$flagSet = $db->getFlag( DBO_TRX );
 		};
@@ -208,7 +208,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 
 		$db->clearFlag( DBO_TRX );
 		$db->onTransactionCommitOrIdle(
-			function ( $trigger, IDatabase $db ) {
+			static function ( $trigger, IDatabase $db ) {
 				$db->setFlag( DBO_TRX );
 			},
 			__METHOD__
@@ -237,7 +237,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 
 		$called = false;
 		$flagSet = null;
-		$callback = function () use ( $db, &$flagSet, &$called ) {
+		$callback = static function () use ( $db, &$flagSet, &$called ) {
 			$called = true;
 			$flagSet = $db->getFlag( DBO_TRX );
 		};
@@ -268,7 +268,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 
 		$db->setFlag( DBO_TRX );
 		try {
-			$db->onTransactionCommitOrIdle( function () {
+			$db->onTransactionCommitOrIdle( static function () {
 				throw new RuntimeException( 'test' );
 			} );
 			$this->fail( "Exception not thrown" );
@@ -290,7 +290,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 
 		$called = false;
 		$db->onTransactionPreCommitOrIdle(
-			function ( IDatabase $db ) use ( &$called ) {
+			static function ( IDatabase $db ) use ( &$called ) {
 				$called = true;
 			},
 			__METHOD__
@@ -300,7 +300,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 		$db->begin( __METHOD__ );
 		$called = false;
 		$db->onTransactionPreCommitOrIdle(
-			function ( IDatabase $db ) use ( &$called ) {
+			static function ( IDatabase $db ) use ( &$called ) {
 				$called = true;
 			},
 			__METHOD__
@@ -331,7 +331,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 		$this->assertFalse( $lb->hasMasterChanges() );
 		$this->assertTrue( $db->getFlag( DBO_TRX ), 'DBO_TRX is set' );
 		$called = false;
-		$callback = function ( IDatabase $db ) use ( &$called ) {
+		$callback = static function ( IDatabase $db ) use ( &$called ) {
 			$called = true;
 		};
 		$db->onTransactionPreCommitOrIdle( $callback, __METHOD__ );
@@ -369,7 +369,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 		$db->clearFlag( DBO_TRX );
 		$db->begin( __METHOD__ );
 		$called = false;
-		$db->onTransactionResolution( function ( $trigger, IDatabase $db ) use ( &$called ) {
+		$db->onTransactionResolution( static function ( $trigger, IDatabase $db ) use ( &$called ) {
 			$called = true;
 			$db->setFlag( DBO_TRX );
 		} );
@@ -380,7 +380,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 		$db->clearFlag( DBO_TRX );
 		$db->begin( __METHOD__ );
 		$called = false;
-		$db->onTransactionResolution( function ( $trigger, IDatabase $db ) use ( &$called ) {
+		$db->onTransactionResolution( static function ( $trigger, IDatabase $db ) use ( &$called ) {
 			$called = true;
 			$db->setFlag( DBO_TRX );
 		} );
@@ -395,7 +395,7 @@ class DatabaseTest extends PHPUnit\Framework\TestCase {
 	public function testTransactionListener() {
 		$db = $this->db;
 
-		$db->setTransactionListener( 'ping', function () use ( $db, &$called ) {
+		$db->setTransactionListener( 'ping', static function () use ( $db, &$called ) {
 			$called = true;
 		} );
 
diff --git a/tests/phpunit/unit/includes/libs/rdbms/resultwrapper/ResultWrapperTest.php b/tests/phpunit/unit/includes/libs/rdbms/resultwrapper/ResultWrapperTest.php
index 53b329d30dc..c8ebdd15443 100644
--- a/tests/phpunit/unit/includes/libs/rdbms/resultwrapper/ResultWrapperTest.php
+++ b/tests/phpunit/unit/includes/libs/rdbms/resultwrapper/ResultWrapperTest.php
@@ -37,7 +37,7 @@ class ResultWrapperTest extends PHPUnit\Framework\TestCase {
 			->disableOriginalConstructor()
 			->getMock();
 		$db->method( 'select' )->willReturnCallback(
-			function () use ( $db, $rows ) {
+			static function () use ( $db, $rows ) {
 				return new ResultWrapper( $db, $rows );
 			}
 		);
@@ -47,19 +47,19 @@ class ResultWrapperTest extends PHPUnit\Framework\TestCase {
 			}
 		);
 		$db->method( 'fetchRow' )->willReturnCallback(
-			function ( ResultWrapper $res ) use ( $db ) {
+			static function ( ResultWrapper $res ) use ( $db ) {
 				return $res::unwrap( $res )[$res->key()] ?? false;
 			}
 		);
 		$db->method( 'fetchObject' )->willReturnCallback(
-			function ( ResultWrapper $res ) use ( $db ) {
+			static function ( ResultWrapper $res ) use ( $db ) {
 				$row = $res::unwrap( $res )[$res->key()] ?? false;
 
 				return $row ? (object)$row : false;
 			}
 		);
 		$db->method( 'numRows' )->willReturnCallback(
-			function ( ResultWrapper $res ) use ( $db ) {
+			static function ( ResultWrapper $res ) use ( $db ) {
 				return count( $res::unwrap( $res ) );
 			}
 		);
diff --git a/tests/phpunit/unit/includes/libs/uuid/GlobalIdGeneratorTest.php b/tests/phpunit/unit/includes/libs/uuid/GlobalIdGeneratorTest.php
index 2cd30031414..e0a574cb1c4 100644
--- a/tests/phpunit/unit/includes/libs/uuid/GlobalIdGeneratorTest.php
+++ b/tests/phpunit/unit/includes/libs/uuid/GlobalIdGeneratorTest.php
@@ -219,7 +219,7 @@ class GlobalIdGeneratorTest extends PHPUnit\Framework\TestCase {
 		$this->globalIdGenerator = new GlobalIdGenerator(
 			wfTempDir(),
 			new HashBagOStuff( [] ),
-			function ( $command ) {
+			static function ( $command ) {
 				return wfShellExec( $command );
 			}
 		);
diff --git a/tests/phpunit/unit/includes/preferences/FiltersTest.php b/tests/phpunit/unit/includes/preferences/FiltersTest.php
index fb057ba07c3..f6713bad16b 100644
--- a/tests/phpunit/unit/includes/preferences/FiltersTest.php
+++ b/tests/phpunit/unit/includes/preferences/FiltersTest.php
@@ -120,7 +120,7 @@ class FiltersTest extends \MediaWikiUnitTestCase {
 			->getMockForAbstractClass();
 
 		$idLookup->method( 'centralIdsFromNames' )
-			->will( self::returnCallback( function ( $names ) use ( $userMapping ) {
+			->will( self::returnCallback( static function ( $names ) use ( $userMapping ) {
 				$ids = [];
 				foreach ( $names as $name ) {
 					$ids[] = $userMapping[$name] ?? null;
@@ -128,7 +128,7 @@ class FiltersTest extends \MediaWikiUnitTestCase {
 				return array_filter( $ids, 'is_numeric' );
 			} ) );
 		$idLookup->method( 'namesFromCentralIds' )
-			->will( self::returnCallback( function ( $ids ) use ( $flipped ) {
+			->will( self::returnCallback( static function ( $ids ) use ( $flipped ) {
 				$names = [];
 				foreach ( $ids as $id ) {
 					$names[] = $flipped[$id] ?? null;
diff --git a/tests/phpunit/unit/includes/search/SearchIndexFieldTest.php b/tests/phpunit/unit/includes/search/SearchIndexFieldTest.php
index a640c967cce..f724d3a16ab 100644
--- a/tests/phpunit/unit/includes/search/SearchIndexFieldTest.php
+++ b/tests/phpunit/unit/includes/search/SearchIndexFieldTest.php
@@ -46,7 +46,7 @@ class SearchIndexFieldTest extends \MediaWikiUnitTestCase {
 		$this->assertFalse( $field1->merge( $field2 ) );
 
 		$field1->setMergeCallback(
-			function ( $a, $b ) {
+			static function ( $a, $b ) {
 				return "test";
 			}
 		);
diff --git a/tests/phpunit/unit/includes/search/SearchSuggestionSetTest.php b/tests/phpunit/unit/includes/search/SearchSuggestionSetTest.php
index 7dc6c42e025..1d78c298e37 100644
--- a/tests/phpunit/unit/includes/search/SearchSuggestionSetTest.php
+++ b/tests/phpunit/unit/includes/search/SearchSuggestionSetTest.php
@@ -44,7 +44,7 @@ class SearchSuggestionSetTest extends \MediaWikiUnitTestCase {
 		$this->assertEquals( 3, $set->getBestScore() );
 		$this->assertSame( 1, $suggestion->getScore() );
 
-		$scores = $set->map( function ( $s ) {
+		$scores = $set->map( static function ( $s ) {
 			return $s->getScore();
 		} );
 		$sorted = $scores;
@@ -84,7 +84,7 @@ class SearchSuggestionSetTest extends \MediaWikiUnitTestCase {
 		$this->assertEquals( 6, $set->getBestScore() );
 		$this->assertEquals( 6, $suggestion->getScore() );
 
-		$scores = $set->map( function ( $s ) {
+		$scores = $set->map( static function ( $s ) {
 			return $s->getScore();
 		} );
 		$sorted = $scores;
diff --git a/tests/phpunit/unit/includes/skins/SkinFactoryTest.php b/tests/phpunit/unit/includes/skins/SkinFactoryTest.php
index f2dab478eeb..79343e91b1b 100644
--- a/tests/phpunit/unit/includes/skins/SkinFactoryTest.php
+++ b/tests/phpunit/unit/includes/skins/SkinFactoryTest.php
@@ -30,7 +30,7 @@ class SkinFactoryTest extends \MediaWikiUnitTestCase {
 		$factory = $this->createSkinFactory();
 		$instance = new SkinFallback();
 
-		$factory->register( 'fallback', 'Fallback', function () use ( $instance ) {
+		$factory->register( 'fallback', 'Fallback', static function () use ( $instance ) {
 			return $instance;
 		} );
 
@@ -63,7 +63,7 @@ class SkinFactoryTest extends \MediaWikiUnitTestCase {
 	 */
 	public function testMakeSkinWithInvalidCallback() {
 		$factory = $this->createSkinFactory();
-		$factory->register( 'unittest', 'Unittest', function () {
+		$factory->register( 'unittest', 'Unittest', static function () {
 			// Not a Skin object
 			return true;
 		} );
@@ -76,7 +76,7 @@ class SkinFactoryTest extends \MediaWikiUnitTestCase {
 	 */
 	public function testMakeSkinWithValidCallback() {
 		$factory = $this->createSkinFactory();
-		$factory->register( 'testfallback', 'TestFallback', function () {
+		$factory->register( 'testfallback', 'TestFallback', static function () {
 			return new SkinFallback();
 		} );
 
@@ -99,7 +99,7 @@ class SkinFactoryTest extends \MediaWikiUnitTestCase {
 		$args = [];
 		$factory = $this->createSkinFactory( $serviceContainer );
 		$factory->register( 'testfallback', 'TestFallback', [
-			'factory' => function ( $service, $options ) use ( &$args ) {
+			'factory' => static function ( $service, $options ) use ( &$args ) {
 				$args = [ $service, $options ];
 				return new SkinFallback();
 			},
diff --git a/tests/phpunit/unit/includes/watcheditem/WatchedItemQueryServiceUnitTest.php b/tests/phpunit/unit/includes/watcheditem/WatchedItemQueryServiceUnitTest.php
index 3cd1c111508..f261b6b58ec 100644
--- a/tests/phpunit/unit/includes/watcheditem/WatchedItemQueryServiceUnitTest.php
+++ b/tests/phpunit/unit/includes/watcheditem/WatchedItemQueryServiceUnitTest.php
@@ -94,7 +94,7 @@ class WatchedItemQueryServiceUnitTest extends MediaWikiUnitTestCase {
 				$this->isType( 'array' ),
 				$this->isType( 'int' )
 			)
-			->will( $this->returnCallback( function ( $a, $conj ) {
+			->will( $this->returnCallback( static function ( $a, $conj ) {
 				$sqlConj = $conj === LIST_AND ? ' AND ' : ' OR ';
 				$conds = [];
 				foreach ( $a as $k => $v ) {
@@ -111,7 +111,7 @@ class WatchedItemQueryServiceUnitTest extends MediaWikiUnitTestCase {
 
 		$mock->expects( $this->any() )
 			->method( 'addQuotes' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				return "'$value'";
 			} ) );
 
@@ -121,7 +121,7 @@ class WatchedItemQueryServiceUnitTest extends MediaWikiUnitTestCase {
 
 		$mock->expects( $this->any() )
 			->method( 'bitAnd' )
-			->willReturnCallback( function ( $a, $b ) {
+			->willReturnCallback( static function ( $a, $b ) {
 				return "($a & $b)";
 			} );
 
@@ -148,7 +148,7 @@ class WatchedItemQueryServiceUnitTest extends MediaWikiUnitTestCase {
 		$mock = $this->createMock( WatchedItemStore::class );
 		$mock->expects( $this->any() )
 			->method( 'getLatestNotificationTimestamp' )
-			->will( $this->returnCallback( function ( $timestamp ) {
+			->will( $this->returnCallback( static function ( $timestamp ) {
 				return $timestamp;
 			} ) );
 		return $mock;
@@ -161,11 +161,11 @@ class WatchedItemQueryServiceUnitTest extends MediaWikiUnitTestCase {
 	private function getMockPermissionManager( $notAllowedAction = null ) {
 		$mock = $this->createMock( PermissionManager::class );
 		$mock->method( 'userHasRight' )
-			->will( $this->returnCallback( function ( $user, $action ) use ( $notAllowedAction ) {
+			->will( $this->returnCallback( static function ( $user, $action ) use ( $notAllowedAction ) {
 				return $action !== $notAllowedAction;
 			} ) );
 		$mock->method( 'userHasAnyRight' )
-			->will( $this->returnCallback( function ( $user, ...$actions ) use ( $notAllowedAction ) {
+			->will( $this->returnCallback( static function ( $user, ...$actions ) use ( $notAllowedAction ) {
 				return !in_array( $notAllowedAction, $actions );
 			} ) );
 		return $mock;
@@ -411,7 +411,7 @@ class WatchedItemQueryServiceUnitTest extends MediaWikiUnitTestCase {
 				$this->isType( 'array' ),
 				$this->isType( 'array' )
 			)
-			->will( $this->returnCallback( function (
+			->will( $this->returnCallback( static function (
 				$user, $options, $db, &$tables, &$fields, &$conds, &$dbOptions, &$joinConds
 			) {
 				$tables[] = 'extension_dummy_table';
@@ -1567,7 +1567,7 @@ class WatchedItemQueryServiceUnitTest extends MediaWikiUnitTestCase {
 		$mockDb = $this->getMockDb();
 		$mockDb->expects( $this->any() )
 			->method( 'addQuotes' )
-			->will( $this->returnCallback( function ( $value ) {
+			->will( $this->returnCallback( static function ( $value ) {
 				return "'$value'";
 			} ) );
 		$mockDb->expects( $this->any() )
@@ -1576,7 +1576,7 @@ class WatchedItemQueryServiceUnitTest extends MediaWikiUnitTestCase {
 				$this->isType( 'array' ),
 				$this->isType( 'int' )
 			)
-			->will( $this->returnCallback( function ( $a, $conj ) {
+			->will( $this->returnCallback( static function ( $a, $conj ) {
 				$sqlConj = $conj === LIST_AND ? ' AND ' : ' OR ';
 				return implode( $sqlConj, array_map( static function ( $s ) {
 					return '(' . $s . ')';