diff -u b/core/modules/ckeditor/tests/src/Unit/Plugin/CKEditorPlugin/LanguageTest.php b/core/modules/ckeditor/tests/src/Unit/Plugin/CKEditorPlugin/LanguageTest.php
--- b/core/modules/ckeditor/tests/src/Unit/Plugin/CKEditorPlugin/LanguageTest.php
+++ b/core/modules/ckeditor/tests/src/Unit/Plugin/CKEditorPlugin/LanguageTest.php
@@ -3,6 +3,7 @@
 namespace Drupal\Tests\ckeditor\Unit\Plugin\CKEditorPlugin;
 
 use Drupal\ckeditor\Plugin\CKEditorPlugin\Language;
+use Drupal\Core\Language\LanguageManager;
 use Drupal\Tests\UnitTestCase;
 
 /**
@@ -31,8 +32,8 @@
    */
   public function providerGetConfig() {
     return [
-      ['un', 6],
-      ['all', 94],
+      ['un', count(LanguageManager::getUnitedNationsLanguageList())],
+      ['all', count(LanguageManager::getStandardLanguageList())],
     ];
   }