diff --git a/lib/phplib/Seminar_Perm.php b/lib/phplib/Seminar_Perm.php
index 1c3a85e95f308b5d615ccbe8ad973dc7fcf60a37..e56835fb1b0a443eb2b0bb56c9a03936984cb5b6 100644
--- a/lib/phplib/Seminar_Perm.php
+++ b/lib/phplib/Seminar_Perm.php
@@ -189,7 +189,11 @@ class Seminar_Perm
             return $status;
         }
 
-        if (Config::get()->DEPUTIES_ENABLE && Deputy::isDeputy($user_id, $range_id)) {
+        if (
+            Config::get()->DEPUTIES_ENABLE
+            && isset($range_id)
+            && Deputy::isDeputy($user_id, $range_id)
+        ) {
             $status = 'dozent';
         } else {
             $st = $db->prepare("SELECT status FROM seminar_user