diff --git a/tests/phpunit/MediaWikiIntegrationTestCase.php b/tests/phpunit/MediaWikiIntegrationTestCase.php
index 83f27e847d..229d71a5de 100644
--- a/tests/phpunit/MediaWikiIntegrationTestCase.php
+++ b/tests/phpunit/MediaWikiIntegrationTestCase.php
@@ -1123,6 +1123,9 @@ public function setContentLang( $lang ) {
             $this->setMwGlobals( 'wgLanguageCode', $lang->getCode() );
         } else {
             $this->setMwGlobals( 'wgLanguageCode', $lang );
+            $services = MediaWikiServices::getInstance();
+            $services->resetServiceForTesting( 'ContentLanguage' );
+            $this->setMwGlobals( [ 'wgContLang' => $services->getContentLanguage() ] );
         }
     }