diff --git a/registration-system/index.php b/registration-system/index.php
index 42253dab95959004d9de067c07890f1e7403b6d7..c74738aaf91a85cb348f0a126550ca345041b9e7 100644
--- a/registration-system/index.php
+++ b/registration-system/index.php
@@ -106,7 +106,7 @@ function index_check_form(){
         goto index_check_form_skip;
     }
 
-    $possible_dates = comm_get_possible_dates($fid);
+    $possible_dates = comm_get_possible_dates($index_db, $fid);
 
     index_check_field('forname', $invalidCharsRegEx, $data, $errors, "Fehlerhafter oder fehlender Vorname!");
     index_check_field('sirname', $invalidCharsRegEx, $data, $errors, "Fehlerhafter oder fehlender Nachname!");