diff --git a/core/lib/Drupal/Core/Language/LanguageManager.php b/core/lib/Drupal/Core/Language/LanguageManager.php
index d29b273..ababc6e 100644
--- a/core/lib/Drupal/Core/Language/LanguageManager.php
+++ b/core/lib/Drupal/Core/Language/LanguageManager.php
@@ -253,7 +253,7 @@ public static function getStandardLanguageList() {
       'dz' => array('Dzongkha', 'རྫོང་ཁ'),
       'el' => array('Greek', 'Ελληνικά'),
       'en' => array('English', 'English'),
-      'en-x-simple' => array('Simple English', 'Simple English'),
+      'enx' => array('Simple English', 'Simple English'),
       'eo' => array('Esperanto', 'Esperanto'),
       'es' => array('Spanish', 'Español'),
       'et' => array('Estonian', 'Eesti')