diff --git a/includes/ServiceWiring.php b/includes/ServiceWiring.php
index cf3c041b5fe..fd21d6c5fbd 100644
--- a/includes/ServiceWiring.php
+++ b/includes/ServiceWiring.php
@@ -792,7 +792,8 @@ return [
 			true,
 			LoggerFactory::getInstance( 'OldRevisionImporter' ),
 			$services->getDBLoadBalancer(),
-			$services->getRevisionStore()
+			$services->getRevisionStore(),
+			$services->getSlotRoleRegistry()
 		);
 	},
 
@@ -1368,7 +1369,8 @@ return [
 			false,
 			LoggerFactory::getInstance( 'OldRevisionImporter' ),
 			$services->getDBLoadBalancer(),
-			$services->getRevisionStore()
+			$services->getRevisionStore(),
+			$services->getSlotRoleRegistry()
 		);
 	},
 
diff --git a/includes/import/ImportableOldRevisionImporter.php b/includes/import/ImportableOldRevisionImporter.php
index b1033d3be5a..ae3a37c9233 100644
--- a/includes/import/ImportableOldRevisionImporter.php
+++ b/includes/import/ImportableOldRevisionImporter.php
@@ -2,6 +2,7 @@
 
 use MediaWiki\Revision\MutableRevisionRecord;
 use MediaWiki\Revision\RevisionStore;
+use MediaWiki\Revision\SlotRoleRegistry;
 use Psr\Log\LoggerInterface;
 use Wikimedia\Rdbms\ILoadBalancer;
 
@@ -30,22 +31,34 @@ class ImportableOldRevisionImporter implements OldRevisionImporter {
 	 */
 	private $revisionStore;
 
+	/**
+	 * @var SlotRoleRegistry
+	 */
+	private $slotRoleRegistry;
+
 	/**
 	 * @param bool $doUpdates
 	 * @param LoggerInterface $logger
 	 * @param ILoadBalancer $loadBalancer
 	 * @param RevisionStore $revisionStore
+	 * @param SlotRoleRegistry|null $slotRoleRegistry
 	 */
 	public function __construct(
 		$doUpdates,
 		LoggerInterface $logger,
 		ILoadBalancer $loadBalancer,
-		RevisionStore $revisionStore
+		RevisionStore $revisionStore,
+		SlotRoleRegistry $slotRoleRegistry = null
 	) {
 		$this->doUpdates = $doUpdates;
 		$this->logger = $logger;
 		$this->loadBalancer = $loadBalancer;
 		$this->revisionStore = $revisionStore;
+		// @todo: temporary - remove when FileImporter extension is updated
+		if ( !$slotRoleRegistry ) {
+			$slotRoleRegistry = \MediaWiki\MediaWikiServices::getInstance()->getSlotRoleRegistry();
+		}
+		$this->slotRoleRegistry = $slotRoleRegistry;
 	}
 
 	public function import( ImportableOldRevision $importableRevision, $doUpdates = true ) {
@@ -144,6 +157,10 @@ class ImportableOldRevisionImporter implements OldRevisionImporter {
 		$originalRevision =
 			$prevRevRow ? $this->revisionStore->newRevisionFromRow( $prevRevRow ) : null;
 		foreach ( $importableRevision->getSlotRoles() as $role ) {
+			if ( !$this->slotRoleRegistry->isDefinedRole( $role ) ) {
+				throw new MWException( "Undefined slot role $role" );
+			}
+
 			$newContent = $importableRevision->getContent( $role );
 			if ( !$originalRevision || !$originalRevision->hasSlot( $role ) ) {
 				$revisionRecord->setContent( $role, $newContent );
diff --git a/tests/phpunit/data/import/UndefinedContentModel.xml b/tests/phpunit/data/import/UndefinedContentModel.xml
new file mode 100644
index 00000000000..3cff369dbb0
--- /dev/null
+++ b/tests/phpunit/data/import/UndefinedContentModel.xml
@@ -0,0 +1,55 @@
+<mediawiki xmlns="http://www.mediawiki.org/xml/export-0.11/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.mediawiki.org/xml/export-0.11/ http://www.mediawiki.org/xml/export-0.11.xsd" version="0.11" xml:lang="de">
+	<siteinfo>
+		<sitename>Test</sitename>
+		<dbname>wiki</dbname>
+		<base>http://example.com/wiki/</base>
+		<generator>MediaWiki Test</generator>
+		<case>first-letter</case>
+		<namespaces>
+			<namespace key="-2" case="first-letter">Medium</namespace>
+			<namespace key="-1" case="first-letter">Spezial</namespace>
+			<namespace key="0" case="first-letter" />
+			<namespace key="1" case="first-letter">Diskussion</namespace>
+			<namespace key="2" case="first-letter">Benutzer</namespace>
+			<namespace key="3" case="first-letter">Benutzer Diskussion</namespace>
+			<namespace key="4" case="first-letter">Project</namespace>
+			<namespace key="5" case="first-letter">Project Diskussion</namespace>
+			<namespace key="6" case="first-letter">Datei</namespace>
+			<namespace key="7" case="first-letter">Datei Diskussion</namespace>
+			<namespace key="8" case="first-letter">MediaWiki</namespace>
+			<namespace key="9" case="first-letter">MediaWiki Diskussion</namespace>
+			<namespace key="10" case="first-letter">Vorlage</namespace>
+			<namespace key="11" case="first-letter">Vorlage Diskussion</namespace>
+			<namespace key="12" case="first-letter">Hilfe</namespace>
+			<namespace key="13" case="first-letter">Hilfe Diskussion</namespace>
+			<namespace key="14" case="first-letter">Kategorie</namespace>
+			<namespace key="15" case="first-letter">Kategorie Diskussion</namespace>
+		</namespaces>
+	</siteinfo>
+	<page>
+		<title>{{page1_title}}</title>
+		<ns>0</ns>
+		<id>1</id>
+		<revision>
+			<id>4</id>
+			<timestamp>2020-07-10T04:11:31Z</timestamp>
+			<contributor>
+				<username>Heffalump</username>
+				<id>3</id>
+			</contributor>
+			<comment>Testing slots</comment>
+			<origin>4</origin>
+			<model>wikitext</model>
+			<format>text/x-wiki</format>
+			<text bytes="5" sha1="syvtbocopvw4f81bf07ocly0sl8ybqo" xml:space="preserve">Hello</text>
+			<content>
+				<role>importfailuretest</role>
+				<origin>4</origin>
+				<model>not-a-defined-model</model>
+				<format>text/x-wiki</format>
+				<text bytes="14" sha1="p2w9gtded1hduym7e0wokxbezokvq8c" xml:space="preserve">This is a slot</text>
+			</content>
+			<sha1>2zn8g94g6g8vb3y98u8wbnxxhtmksm6</sha1>
+		</revision>
+	</page>
+</mediawiki>
diff --git a/tests/phpunit/data/import/UnknownSlotRole.xml b/tests/phpunit/data/import/UndefinedSlotRole.xml
similarity index 100%
rename from tests/phpunit/data/import/UnknownSlotRole.xml
rename to tests/phpunit/data/import/UndefinedSlotRole.xml
diff --git a/tests/phpunit/includes/import/ImportFailureTest.php b/tests/phpunit/includes/import/ImportFailureTest.php
index 9cd40c4b191..df207b65194 100644
--- a/tests/phpunit/includes/import/ImportFailureTest.php
+++ b/tests/phpunit/includes/import/ImportFailureTest.php
@@ -81,8 +81,8 @@ class ImportFailureTest extends MediaWikiLangTestCase {
 		yield [ 'MissingMainTextField', 'MWException', '/^Missing text field in import.$/' ];
 		yield [ 'MissingSlotTextField', 'MWException', '/^Missing text field in import.$/' ];
 		yield [ 'MissingSlotRole', 'MWException', '/^Missing role for imported slot.$/' ];
-		yield [ 'UnknownSlotRole', 'PHPUnit\Framework\Error\Notice',
-			'/SlotRoleRegistry::getRoleHandler: known but undefined slot role/' ];
+		yield [ 'UndefinedSlotRole', 'MWException', '/^Undefined slot role .*$/' ];
+		yield [ 'UndefinedContentModel', 'MWException', '/not registered on this wiki/' ];
 	}
 
 	/**
diff --git a/tests/phpunit/includes/import/ImportableOldRevisionImporterTest.php b/tests/phpunit/includes/import/ImportableOldRevisionImporterTest.php
index de0048c6851..3ff6ee89783 100644
--- a/tests/phpunit/includes/import/ImportableOldRevisionImporterTest.php
+++ b/tests/phpunit/includes/import/ImportableOldRevisionImporterTest.php
@@ -43,7 +43,8 @@ class ImportableOldRevisionImporterTest extends MediaWikiIntegrationTestCase {
 			true,
 			new NullLogger(),
 			$services->getDBLoadBalancer(),
-			$services->getRevisionStore()
+			$services->getRevisionStore(),
+			$services->getSlotRoleRegistry()
 		);
 		$result = $importer->import( $revision );
 		$this->assertTrue( $result );