diff --git a/admin/check/check_php_inc.php b/admin/check/check_php_inc.php
index 52e6e73a05..105266e677 100644
--- a/admin/check/check_php_inc.php
+++ b/admin/check/check_php_inc.php
@@ -51,7 +51,8 @@
 	'pcre',
 	'Reflection',
 	'session',
-	'mbstring'
+	'mbstring',
+	'json'
 );
 
 foreach( $t_extensions_required as $t_extension ) {