diff --git a/app/controllers/course/timesrooms.php b/app/controllers/course/timesrooms.php
index b2ca347166cb77d3efb120df98e85abe584d7304..18792bb626aba9b8d65540dd368f69737d439c21 100644
--- a/app/controllers/course/timesrooms.php
+++ b/app/controllers/course/timesrooms.php
@@ -1417,7 +1417,7 @@ class Course_TimesroomsController extends AuthenticatedController
     /**
      * Deletes a date.
      *
-     * @param String $termin CourseDate of the date
+     * @param CourseDate $termin CourseDate of the date
      * @param String $cancel_comment cancel mesessage (if non empty)
      *
      * @return CourseDate|CourseExDate deleted date
@@ -1425,7 +1425,6 @@ class Course_TimesroomsController extends AuthenticatedController
     private function deleteDate($termin, $cancel_comment)
     {
         $seminar_id = $termin->range_id;
-        $termin_id = $termin->id;
         $termin_room = $termin->getRoomName();
         $termin_date = $termin->getFullname();
         $has_topics  = $termin->topics->count();
@@ -1441,12 +1440,6 @@ class Course_TimesroomsController extends AuthenticatedController
         } else {
             if ($termin->delete()) {
                 StudipLog::log("SEM_DELETE_SINGLEDATE", $termin->id, $seminar_id, 'appointment cancelled');
-
-                // delete attached resource request appointments if they exist
-                ResourceRequestAppointment::deleteBySQL(
-                    "appointment_id = ?",
-                    [$termin_id]
-                );
             }
         }
 
diff --git a/lib/models/CourseDate.class.php b/lib/models/CourseDate.class.php
index 9060797f8c3dc8864816330a567daa88b75b5327..91c357934069f01e2a11b3f540ceecfaa2940042 100644
--- a/lib/models/CourseDate.class.php
+++ b/lib/models/CourseDate.class.php
@@ -100,6 +100,11 @@ class CourseDate extends SimpleORMap implements PrivacyObject
             'assoc_foreign_key' => 'termin_id',
             'on_delete'         => 'delete',
         ];
+        $config['has_many']['resource_request_appointments'] = [
+            'class_name'        => ResourceRequestAppointment::class,
+            'assoc_foreign_key' => 'appointment_id',
+            'on_delete'         => 'delete',
+        ];
         $config['default_values']['date_typ'] = 1;
         parent::configure($config);
     }