diff --git a/install/lang/mn/langconfig.php b/install/lang/mn/langconfig.php
index 277de8c2d4e..d69759eb3ed 100644
--- a/install/lang/mn/langconfig.php
+++ b/install/lang/mn/langconfig.php
@@ -29,5 +29,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
+$string['parentlanguage'] = '';
 $string['thisdirection'] = 'ltr';
 $string['thislanguage'] = 'Монгол';