diff --git a/includes/MergeHistory.php b/includes/MergeHistory.php
index 0e9bb4673d9..4c655ebab53 100644
--- a/includes/MergeHistory.php
+++ b/includes/MergeHistory.php
@@ -167,7 +167,7 @@ class MergeHistory {
 		// Convert into a Status object
 		if ( $errors ) {
 			foreach ( $errors as $error ) {
-				call_user_func_array( [ $status, 'fatal' ], $error );
+				$status->fatal( ...$error );
 			}
 		}
 
diff --git a/includes/MovePage.php b/includes/MovePage.php
index fc9f6a66766..3210ba8eb0e 100644
--- a/includes/MovePage.php
+++ b/includes/MovePage.php
@@ -57,7 +57,7 @@ class MovePage {
 		// Convert into a Status object
 		if ( $errors ) {
 			foreach ( $errors as $error ) {
-				call_user_func_array( [ $status, 'fatal' ], $error );
+				$status->fatal( ...$error );
 			}
 		}
 
diff --git a/includes/OutputPage.php b/includes/OutputPage.php
index c51f6f8ec26..f92f4f38dac 100644
--- a/includes/OutputPage.php
+++ b/includes/OutputPage.php
@@ -2645,13 +2645,13 @@ class OutputPage extends ContextSource {
 
 			foreach ( $errors as $error ) {
 				$text .= '<li>';
-				$text .= call_user_func_array( [ $this, 'msg' ], $error )->plain();
+				$text .= $this->msg( ...$error )->plain();
 				$text .= "</li>\n";
 			}
 			$text .= '</ul>';
 		} else {
 			$text .= "<div class=\"permissions-errors\">\n" .
-					call_user_func_array( [ $this, 'msg' ], reset( $errors ) )->plain() .
+					$this->msg( ...reset( $errors ) )->plain() .
 					"\n</div>";
 		}
 
diff --git a/includes/Storage/RevisionRecord.php b/includes/Storage/RevisionRecord.php
index ff0a70dd243..66ec2c07a2e 100644
--- a/includes/Storage/RevisionRecord.php
+++ b/includes/Storage/RevisionRecord.php
@@ -474,7 +474,7 @@ abstract class RevisionRecord {
 			$permissionlist = implode( ', ', $permissions );
 			if ( $title === null ) {
 				wfDebug( "Checking for $permissionlist due to $field match on $bitfield\n" );
-				return call_user_func_array( [ $user, 'isAllowedAny' ], $permissions );
+				return $user->isAllowedAny( ...$permissions );
 			} else {
 				$text = $title->getPrefixedText();
 				wfDebug( "Checking for $permissionlist on $text due to $field match on $bitfield\n" );
diff --git a/includes/api/ApiQueryLinks.php b/includes/api/ApiQueryLinks.php
index 67bf619c894..144c7582b03 100644
--- a/includes/api/ApiQueryLinks.php
+++ b/includes/api/ApiQueryLinks.php
@@ -103,7 +103,7 @@ class ApiQueryLinks extends ApiQueryGeneratorBase {
 			if ( $cond ) {
 				$this->addWhere( $cond );
 				$multiNS = count( $lb->data ) !== 1;
-				$multiTitle = count( call_user_func_array( 'array_merge', $lb->data ) ) !== 1;
+				$multiTitle = count( array_merge( ...$lb->data ) ) !== 1;
 			} else {
 				// No titles so no results
 				return;
diff --git a/includes/api/ApiQueryTokens.php b/includes/api/ApiQueryTokens.php
index e86fdf35331..8854aac0de3 100644
--- a/includes/api/ApiQueryTokens.php
+++ b/includes/api/ApiQueryTokens.php
@@ -94,7 +94,7 @@ class ApiQueryTokens extends ApiQueryBase {
 	public static function getToken( User $user, MediaWiki\Session\Session $session, $salt ) {
 		if ( is_array( $salt ) ) {
 			$session->persist();
-			return call_user_func_array( [ $session, 'getToken' ], $salt );
+			return $session->getToken( ...$salt );
 		} else {
 			return $user->getEditTokenObject( $salt, $session->getRequest() );
 		}
diff --git a/includes/api/ApiQueryUserContribs.php b/includes/api/ApiQueryUserContribs.php
index 420d138df7a..fdcaa769323 100644
--- a/includes/api/ApiQueryUserContribs.php
+++ b/includes/api/ApiQueryUserContribs.php
@@ -306,9 +306,11 @@ class ApiQueryUserContribs extends ApiQueryBase {
 				foreach ( $res as $row ) {
 					$names[$row->user_name] = $row;
 				}
-				call_user_func_array(
-					$this->params['dir'] == 'newer' ? 'ksort' : 'krsort', [ &$names, SORT_STRING ]
-				);
+				if ( $this->params['dir'] == 'newer' ) {
+					ksort( $names, SORT_STRING );
+				} else {
+					krsort( $names, SORT_STRING );
+				}
 				$neg = $op === '>' ? -1 : 1;
 				$userIter = call_user_func( function () use ( $names, $fromName, $neg ) {
 					foreach ( $names as $name => $row ) {
diff --git a/includes/auth/ButtonAuthenticationRequest.php b/includes/auth/ButtonAuthenticationRequest.php
index d274e18f7b1..1268e68de5e 100644
--- a/includes/auth/ButtonAuthenticationRequest.php
+++ b/includes/auth/ButtonAuthenticationRequest.php
@@ -90,14 +90,14 @@ class ButtonAuthenticationRequest extends AuthenticationRequest {
 		} elseif ( is_string( $data['label'] ) ) {
 			$data['label'] = new \Message( $data['label'] );
 		} elseif ( is_array( $data['label'] ) ) {
-			$data['label'] = call_user_func_array( 'Message::newFromKey', $data['label'] );
+			$data['label'] = Message::newFromKey( ...$data['label'] );
 		}
 		if ( !isset( $data['help'] ) ) {
 			$data['help'] = new \RawMessage( '$1', $data['name'] );
 		} elseif ( is_string( $data['help'] ) ) {
 			$data['help'] = new \Message( $data['help'] );
 		} elseif ( is_array( $data['help'] ) ) {
-			$data['help'] = call_user_func_array( 'Message::newFromKey', $data['help'] );
+			$data['help'] = Message::newFromKey( ...$data['help'] );
 		}
 		$ret = new static( $data['name'], $data['label'], $data['help'] );
 		foreach ( $data as $k => $v ) {
diff --git a/includes/exception/MWExceptionHandler.php b/includes/exception/MWExceptionHandler.php
index 79f0a233749..9039cfca945 100644
--- a/includes/exception/MWExceptionHandler.php
+++ b/includes/exception/MWExceptionHandler.php
@@ -173,9 +173,7 @@ class MWExceptionHandler {
 		global $wgPropagateErrors;
 
 		if ( in_array( $level, self::$fatalErrorTypes ) ) {
-			return call_user_func_array(
-				'MWExceptionHandler::handleFatalError', func_get_args()
-			);
+			return self::handleFatalError( ...func_get_args() );
 		}
 
 		// Map error constant to error name (reverse-engineer PHP error
diff --git a/includes/htmlform/HTMLForm.php b/includes/htmlform/HTMLForm.php
index 785d30f8a30..e72faa0e30d 100644
--- a/includes/htmlform/HTMLForm.php
+++ b/includes/htmlform/HTMLForm.php
@@ -607,7 +607,7 @@ class HTMLForm extends ContextSource {
 		$hoistedErrors = Status::newGood();
 		if ( $this->mValidationErrorMessage ) {
 			foreach ( (array)$this->mValidationErrorMessage as $error ) {
-				call_user_func_array( [ $hoistedErrors, 'fatal' ], $error );
+				$hoistedErrors->fatal( ...$error );
 			}
 		} else {
 			$hoistedErrors->fatal( 'htmlform-invalid-input' );
diff --git a/includes/installer/WebInstaller.php b/includes/installer/WebInstaller.php
index 8fb980791e7..306afc4e93a 100644
--- a/includes/installer/WebInstaller.php
+++ b/includes/installer/WebInstaller.php
@@ -717,7 +717,7 @@ class WebInstaller extends Installer {
 	 */
 	public function showHelpBox( $msg /*, ... */ ) {
 		$args = func_get_args();
-		$html = call_user_func_array( [ $this, 'getHelpBox' ], $args );
+		$html = $this->getHelpBox( ...$args );
 		$this->output->addHTML( $html );
 	}
 
@@ -742,7 +742,7 @@ class WebInstaller extends Installer {
 	public function showStatusMessage( Status $status ) {
 		$errors = array_merge( $status->getErrorsArray(), $status->getWarningsArray() );
 		foreach ( $errors as $error ) {
-			call_user_func_array( [ $this, 'showMessage' ], $error );
+			$this->showMessage( ...$error );
 		}
 	}
 
diff --git a/includes/libs/StatusValue.php b/includes/libs/StatusValue.php
index 6f348c2b96e..3bdafe12820 100644
--- a/includes/libs/StatusValue.php
+++ b/includes/libs/StatusValue.php
@@ -68,7 +68,7 @@ class StatusValue {
 	public static function newFatal( $message /*, parameters...*/ ) {
 		$params = func_get_args();
 		$result = new static();
-		call_user_func_array( [ &$result, 'fatal' ], $params );
+		$result->fatal( ...$params );
 		return $result;
 	}
 
diff --git a/includes/libs/filebackend/FileBackend.php b/includes/libs/filebackend/FileBackend.php
index 2d4a772b7e7..785cb726554 100644
--- a/includes/libs/filebackend/FileBackend.php
+++ b/includes/libs/filebackend/FileBackend.php
@@ -1590,7 +1590,7 @@ abstract class FileBackend implements LoggerAwareInterface {
 	final protected function newStatus() {
 		$args = func_get_args();
 		if ( count( $args ) ) {
-			$sv = call_user_func_array( [ StatusValue::class, 'newFatal' ], $args );
+			$sv = StatusValue::newFatal( ...$args );
 		} else {
 			$sv = StatusValue::newGood();
 		}
diff --git a/includes/libs/lockmanager/MemcLockManager.php b/includes/libs/lockmanager/MemcLockManager.php
index ebd72de894e..f1f749faa03 100644
--- a/includes/libs/lockmanager/MemcLockManager.php
+++ b/includes/libs/lockmanager/MemcLockManager.php
@@ -89,7 +89,7 @@ class MemcLockManager extends QuorumLockManager {
 
 		$memc = $this->getCache( $lockSrv );
 		// List of affected paths
-		$paths = call_user_func_array( 'array_merge', array_values( $pathsByType ) );
+		$paths = array_merge( ...array_values( $pathsByType ) );
 		$paths = array_unique( $paths );
 		// List of affected lock record keys
 		$keys = array_map( [ $this, 'recordKeyForPath' ], $paths );
@@ -164,7 +164,7 @@ class MemcLockManager extends QuorumLockManager {
 
 		$memc = $this->getCache( $lockSrv );
 		// List of affected paths
-		$paths = call_user_func_array( 'array_merge', array_values( $pathsByType ) );
+		$paths = array_merge( ...array_values( $pathsByType ) );
 		$paths = array_unique( $paths );
 		// List of affected lock record keys
 		$keys = array_map( [ $this, 'recordKeyForPath' ], $paths );
diff --git a/includes/libs/lockmanager/RedisLockManager.php b/includes/libs/lockmanager/RedisLockManager.php
index ea9dde7f2a0..a624f0a9710 100644
--- a/includes/libs/lockmanager/RedisLockManager.php
+++ b/includes/libs/lockmanager/RedisLockManager.php
@@ -76,7 +76,7 @@ class RedisLockManager extends QuorumLockManager {
 	protected function getLocksOnServer( $lockSrv, array $pathsByType ) {
 		$status = StatusValue::newGood();
 
-		$pathList = call_user_func_array( 'array_merge', array_values( $pathsByType ) );
+		$pathList = array_merge( ...array_values( $pathsByType ) );
 
 		$server = $this->lockServers[$lockSrv];
 		$conn = $this->redisPool->getConnection( $server, $this->logger );
@@ -171,7 +171,7 @@ LUA;
 	protected function freeLocksOnServer( $lockSrv, array $pathsByType ) {
 		$status = StatusValue::newGood();
 
-		$pathList = call_user_func_array( 'array_merge', array_values( $pathsByType ) );
+		$pathList = array_merge( ...array_values( $pathsByType ) );
 
 		$server = $this->lockServers[$lockSrv];
 		$conn = $this->redisPool->getConnection( $server, $this->logger );
diff --git a/includes/logging/LogEventsList.php b/includes/logging/LogEventsList.php
index 9e4a630bd08..40498cd558c 100644
--- a/includes/logging/LogEventsList.php
+++ b/includes/logging/LogEventsList.php
@@ -553,7 +553,7 @@ class LogEventsList extends ContextSource {
 			}
 			$permissionlist = implode( ', ', $permissions );
 			wfDebug( "Checking for $permissionlist due to $field match on $bitfield\n" );
-			return call_user_func_array( [ $user, 'isAllowedAny' ], $permissions );
+			return $user->isAllowedAny( ...$permissions );
 		}
 		return true;
 	}
diff --git a/includes/media/BitmapHandler.php b/includes/media/BitmapHandler.php
index cda037c16d3..4cb7c87ec01 100644
--- a/includes/media/BitmapHandler.php
+++ b/includes/media/BitmapHandler.php
@@ -228,7 +228,7 @@ class BitmapHandler extends TransformationalImageHandler {
 		$rotation = isset( $params['disableRotation'] ) ? 0 : $this->getRotation( $image );
 		list( $width, $height ) = $this->extractPreRotationDimensions( $params, $rotation );
 
-		$cmd = call_user_func_array( 'wfEscapeShellArg', array_merge(
+		$cmd = wfEscapeShellArg( ...array_merge(
 			[ $wgImageMagickConvertCommand ],
 			$quality,
 			// Specify white background color, will be used for transparent images
diff --git a/includes/parser/Parser.php b/includes/parser/Parser.php
index 8df5b5ba09e..15ed93c5ff2 100644
--- a/includes/parser/Parser.php
+++ b/includes/parser/Parser.php
@@ -3435,7 +3435,7 @@ class Parser {
 			}
 		}
 
-		$result = call_user_func_array( $callback, $allArgs );
+		$result = $callback( ...$allArgs );
 
 		# The interface for function hooks allows them to return a wikitext
 		# string or an array containing the string and any flags. This mungs
diff --git a/includes/parser/ParserOutput.php b/includes/parser/ParserOutput.php
index 9ec6cf82b27..265d1516a67 100644
--- a/includes/parser/ParserOutput.php
+++ b/includes/parser/ParserOutput.php
@@ -311,10 +311,10 @@ class ParserOutput extends CacheTime {
 					}
 
 					$skin = $wgOut->getSkin();
-					return call_user_func_array(
-						[ $skin, 'doEditSectionLink' ],
-						[ $editsectionPage, $editsectionSection,
-							$editsectionContent, $wgLang->getCode() ]
+					return $skin->doEditSectionLink( $editsectionPage,
+						$editsectionSection,
+						$editsectionContent,
+						$wgLang->getCode()
 					);
 				},
 				$text
diff --git a/includes/resourceloader/ResourceLoaderContext.php b/includes/resourceloader/ResourceLoaderContext.php
index d41198ae553..3ceb915d276 100644
--- a/includes/resourceloader/ResourceLoaderContext.php
+++ b/includes/resourceloader/ResourceLoaderContext.php
@@ -226,7 +226,7 @@ class ResourceLoaderContext implements MessageLocalizer {
 	 * @return Message
 	 */
 	public function msg( $key ) {
-		return call_user_func_array( 'wfMessage', func_get_args() )
+		return wfMessage( ...func_get_args() )
 			->inLanguage( $this->getLanguage() )
 			// Use a dummy title because there is no real title
 			// for this endpoint, and the cache won't vary on it
diff --git a/includes/skins/BaseTemplate.php b/includes/skins/BaseTemplate.php
index d1bea8d1b20..683877439e5 100644
--- a/includes/skins/BaseTemplate.php
+++ b/includes/skins/BaseTemplate.php
@@ -36,7 +36,7 @@ abstract class BaseTemplate extends QuickTemplate {
 	 * @return Message
 	 */
 	public function getMsg( $name /* ... */ ) {
-		return call_user_func_array( [ $this->getSkin(), 'msg' ], func_get_args() );
+		return $this->getSkin()->msg( ...func_get_args() );
 	}
 
 	function msg( $str ) {
diff --git a/includes/specialpage/AuthManagerSpecialPage.php b/includes/specialpage/AuthManagerSpecialPage.php
index 81e13f00f03..557bd9cc5ae 100644
--- a/includes/specialpage/AuthManagerSpecialPage.php
+++ b/includes/specialpage/AuthManagerSpecialPage.php
@@ -432,11 +432,11 @@ abstract class AuthManagerSpecialPage extends SpecialPage {
 				$status = Status::newFatal( new RawMessage( '$1', $status ) );
 			} elseif ( is_array( $status ) ) {
 				if ( is_string( reset( $status ) ) ) {
-					$status = call_user_func_array( 'Status::newFatal', $status );
+					$status = Status::newFatal( ...$status );
 				} elseif ( is_array( reset( $status ) ) ) {
 					$status = Status::newGood();
 					foreach ( $status as $message ) {
-						call_user_func_array( [ $status, 'fatal' ], $message );
+						$status->fatal( ...$message );
 					}
 				} else {
 					throw new UnexpectedValueException( 'invalid HTMLForm::trySubmit() return value: '
diff --git a/includes/specialpage/ChangesListSpecialPage.php b/includes/specialpage/ChangesListSpecialPage.php
index 0622584331c..831644ef2fa 100644
--- a/includes/specialpage/ChangesListSpecialPage.php
+++ b/includes/specialpage/ChangesListSpecialPage.php
@@ -704,9 +704,8 @@ abstract class ChangesListSpecialPage extends SpecialPage {
 			return;
 		}
 
-		$knownParams = call_user_func_array(
-			[ $this->getRequest(), 'getValues' ],
-			array_keys( $this->getOptions()->getAllValues() )
+		$knownParams = $this->getRequest()->getValues(
+			...array_keys( $this->getOptions()->getAllValues() )
 		);
 
 		// HACK: Temporarily until we can properly define "sticky" filters and parameters,
diff --git a/includes/specialpage/SpecialPage.php b/includes/specialpage/SpecialPage.php
index 317aa0d7c84..5db8066228a 100644
--- a/includes/specialpage/SpecialPage.php
+++ b/includes/specialpage/SpecialPage.php
@@ -791,10 +791,7 @@ class SpecialPage implements MessageLocalizer {
 	 * @see wfMessage
 	 */
 	public function msg( $key /* $args */ ) {
-		$message = call_user_func_array(
-			[ $this->getContext(), 'msg' ],
-			func_get_args()
-		);
+		$message = $this->getContext()->msg( ...func_get_args() );
 		// RequestContext passes context to wfMessage, and the language is set from
 		// the context, but setting the language for Message class removes the
 		// interface message status, which breaks for example usernameless gender
diff --git a/includes/specials/SpecialBlock.php b/includes/specials/SpecialBlock.php
index efe354a3465..bc632b1c0d6 100644
--- a/includes/specials/SpecialBlock.php
+++ b/includes/specials/SpecialBlock.php
@@ -553,7 +553,7 @@ class SpecialBlock extends FormSpecialPage {
 		if ( !$status->isOK() ) {
 			$errors = $status->getErrorsArray();
 
-			return call_user_func_array( [ $form, 'msg' ], $errors[0] );
+			return $form->msg( ...$errors[0] );
 		} else {
 			return true;
 		}
diff --git a/includes/upload/UploadBase.php b/includes/upload/UploadBase.php
index 6a471ba573e..5352d95b8de 100644
--- a/includes/upload/UploadBase.php
+++ b/includes/upload/UploadBase.php
@@ -854,7 +854,7 @@ abstract class UploadBase {
 			if ( !is_array( $error ) ) {
 				$error = [ $error ];
 			}
-			return call_user_func_array( 'Status::newFatal', $error );
+			return Status::newFatal( ...$error );
 		}
 
 		$status = $this->getLocalFile()->upload(
@@ -1063,7 +1063,7 @@ abstract class UploadBase {
 		if ( !$isPartial ) {
 			$error = $this->runUploadStashFileHook( $user );
 			if ( $error ) {
-				return call_user_func_array( 'Status::newFatal', $error );
+				return Status::newFatal( ...$error );
 			}
 		}
 		try {
diff --git a/includes/upload/UploadFromChunks.php b/includes/upload/UploadFromChunks.php
index 68bcb9d9c74..ee6f250a766 100644
--- a/includes/upload/UploadFromChunks.php
+++ b/includes/upload/UploadFromChunks.php
@@ -210,7 +210,7 @@ class UploadFromChunks extends UploadFromFile {
 		// override doStashFile() with completely different functionality in this class...
 		$error = $this->runUploadStashFileHook( $this->user );
 		if ( $error ) {
-			call_user_func_array( [ $status, 'fatal' ], $error );
+			$status->fatal( ...$error );
 			return $status;
 		}
 		try {
@@ -422,9 +422,9 @@ class UploadChunkFileException extends MWException {
 
 class UploadChunkVerificationException extends MWException {
 	public $msg;
-	public function __construct( $res ) {
-		$this->msg = call_user_func_array( 'wfMessage', $res );
-		parent::__construct( call_user_func_array( 'wfMessage', $res )
+	public function __construct( array $res ) {
+		$this->msg = wfMessage( ...$res );
+		parent::__construct( wfMessage( ...$res )
 			->inLanguage( 'en' )->useDatabase( false )->text() );
 	}
 }
diff --git a/maintenance/backup.inc b/maintenance/backup.inc
index 0fdd417fc39..21d9bb1639b 100644
--- a/maintenance/backup.inc
+++ b/maintenance/backup.inc
@@ -142,7 +142,7 @@ class BackupDumper extends Maintenance {
 			require_once $file;
 		}
 		$register = [ $class, 'register' ];
-		call_user_func_array( $register, [ $this ] );
+		$register( $this );
 	}
 
 	function execute() {
diff --git a/maintenance/storage/recompressTracked.php b/maintenance/storage/recompressTracked.php
index 49b8e0a69d6..271cbf3dd6e 100644
--- a/maintenance/storage/recompressTracked.php
+++ b/maintenance/storage/recompressTracked.php
@@ -226,7 +226,7 @@ class RecompressTracked {
 		}
 		$cmd .= ' --child' .
 			' --wiki ' . wfEscapeShellArg( wfWikiID() ) .
-			' ' . call_user_func_array( 'wfEscapeShellArg', $this->destClusters );
+			' ' . wfEscapeShellArg( ...$this->destClusters );
 
 		$this->replicaPipes = $this->replicaProcs = [];
 		for ( $i = 0; $i < $this->numProcs; $i++ ) {
@@ -426,12 +426,12 @@ class RecompressTracked {
 				$args = array_slice( $ids, 0, $this->orphanBatchSize );
 				$ids = array_slice( $ids, $this->orphanBatchSize );
 				array_unshift( $args, 'doOrphanList' );
-				call_user_func_array( [ $this, 'dispatch' ], $args );
+				$this->dispatch( ...$args );
 			}
 			if ( count( $ids ) ) {
 				$args = $ids;
 				array_unshift( $args, 'doOrphanList' );
-				call_user_func_array( [ $this, 'dispatch' ], $args );
+				$this->dispatch( ...$args );
 			}
 
 			$this->report( 'orphans', $i, $numOrphans );