diff --git a/application/libraries/treemenu/StudVwLib.php b/application/libraries/treemenu/StudVwLib.php
index c986f2ba0..326ad9f70 100644
--- a/application/libraries/treemenu/StudVwLib.php
+++ b/application/libraries/treemenu/StudVwLib.php
@@ -80,7 +80,9 @@ class StudVwLib
 
 	public function prestudent($path_template, $stg)
 	{
-		// TODO(chris): permission check stg
+		// Check permission
+		if ($this->getStgFromUrl($stg) === null)
+			return [];
 
 		return [
 			[