diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index b7ac23d..90ab40d 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -531,6 +531,7 @@ function user_access($string, $account = NULL) {
       $perms += $one_role;
     }
     $perm[$account->uid] = $perms;
+    drupal_alter('user_access', $perms);
   }
 
   return isset($perm[$account->uid][$string]);