diff --git a/interface/lib/classes/auth.inc.php b/interface/lib/classes/auth.inc.php
index 36ec114c0f692ab506bb6a8896815f56f5eec061..706dd04090ce6384e20192053ede23a5bb57d2df 100644
--- a/interface/lib/classes/auth.inc.php
+++ b/interface/lib/classes/auth.inc.php
@@ -33,6 +33,7 @@ class auth {
 
 	public function get_user_id()
 	{
+		global $app;
 		return $app->functions->intval($_SESSION['s']['user']['userid']);
 	}