diff --git a/user/controllers/YumInstallController.php b/user/controllers/YumInstallController.php
index b582690..f851d17 100755
--- a/user/controllers/YumInstallController.php
+++ b/user/controllers/YumInstallController.php
@@ -301,7 +301,7 @@ public function actionInstall()
 
               $sql = "CREATE TABLE IF NOT EXISTS `" . $permissionTable . "` (
                 `principal_id` int(11) NOT NULL,
-                `subordinate_id` int(11) NULL,
+                `subordinate_id` int(11) NOT NULL,
                 `type` enum('user','role') NOT NULL,
                 `action` int(11) unsigned NOT NULL,
                 `subaction` int(11) unsigned NOT NULL,