diff --git a/data/LanguageNameIndexer.php b/data/LanguageNameIndexer.php
index deb2b59d..e16d1513 100644
--- a/data/LanguageNameIndexer.php
+++ b/data/LanguageNameIndexer.php
@@ -24,6 +24,9 @@ if ( $IP === false ) {
 }
 require_once "$IP/maintenance/Maintenance.php";
 
+use MediaWiki\Languages\LanguageNameUtils;
+use MediaWiki\MediaWikiServices;
+
 class LanguageNameIndexer extends Maintenance {
 	public function __construct() {
 		parent::__construct();
@@ -51,7 +54,8 @@ class LanguageNameIndexer extends Maintenance {
 		// Languages and their names in different languages from Names.php and the cldr extension
 		// This comes after $ulsLanguages so that for example the als/gsw mixup is using the code
 		// used in the Wikimedia world.
-		$mwLanguages = Language::fetchLanguageNames( null, 'all' );
+		$mwLanguages = MediaWikiServices::getInstance()->getLanguageNameUtils()
+			->getLanguageNames( LanguageNameUtils::AUTONYMS, LanguageNameUtils::ALL );
 		foreach ( array_keys( $mwLanguages ) as $languageCode ) {
 			$languageNames[ $languageCode ] = LanguageNames::getNames( $languageCode, 0, 2 );
 		}
diff --git a/includes/ResourceLoaderULSModule.php b/includes/ResourceLoaderULSModule.php
index c15f6259..3efc3989 100644
--- a/includes/ResourceLoaderULSModule.php
+++ b/includes/ResourceLoaderULSModule.php
@@ -21,7 +21,8 @@
 
 namespace UniversalLanguageSelector;
 
-use Language;
+use MediaWiki\Languages\LanguageNameUtils;
+use MediaWiki\MediaWikiServices;
 use ResourceLoader;
 use ResourceLoaderContext;
 use ResourceLoaderModule;
@@ -41,9 +42,9 @@ class ResourceLoaderULSModule extends ResourceLoaderModule {
 	 */
 	private function getData( $languageCode ) {
 		$vars = [];
-		$vars['wgULSLanguages'] = Language::fetchLanguageNames(
+		$vars['wgULSLanguages'] = MediaWikiServices::getInstance()->getLanguageNameUtils()->getLanguageNames(
 			$languageCode,
-			'mwfile'
+			LanguageNameUtils::SUPPORTED
 		);
 		return $vars;
 	}