diff --git a/install/lang/zh_cn/langconfig.php b/install/lang/zh_cn/langconfig.php
index 23878bb831f..0bc12e9714c 100644
--- a/install/lang/zh_cn/langconfig.php
+++ b/install/lang/zh_cn/langconfig.php
@@ -30,5 +30,6 @@
 
 defined('MOODLE_INTERNAL') || die();
 
+$string['parentlanguage'] = '';
 $string['thisdirection'] = 'ltr';
 $string['thislanguage'] = '简体中文';