diff --git a/lib/classes/Seminar.class.php b/lib/classes/Seminar.class.php
index 18c045f62bc6794525e40b317c2b07d724c70b26..33fc50b5bc43e966af3956020a515a2ee3dcc661 100644
--- a/lib/classes/Seminar.class.php
+++ b/lib/classes/Seminar.class.php
@@ -1551,12 +1551,7 @@ class Seminar
             $this->createMessage(sprintf(_('%s Funktionen/Gruppen gelöscht.'), $count));
         }
 
-        // Alle Eintraege aus dem Vorlesungsverzeichnis rauswerfen
-        $sem_tree = TreeAbstract::GetInstance('StudipSemTree');
-        $db_ar = $sem_tree->DeleteSemEntries(null, $s_id);
-        if ($db_ar > 0) {
-            $this->createMessage(sprintf(_("%s Zuordnungen zu Bereichen archiviert."), $db_ar));
-        }
+        // seminar_sem_tree entries are deleted automatically on deletion of the Course object.
 
         // Alle Termine mit allem was dranhaengt zu diesem Seminar loeschen.
         if (($db_ar = SingleDateDB::deleteAllDates($s_id)) > 0) {
diff --git a/lib/models/StudipStudyArea.class.php b/lib/models/StudipStudyArea.class.php
index 877b5a86396558c538b848901e6afb0fa4a3a64b..74c50a7840979078e7bed2af800cc59c3980c701 100644
--- a/lib/models/StudipStudyArea.class.php
+++ b/lib/models/StudipStudyArea.class.php
@@ -21,7 +21,6 @@
  * @property string priority database column
  * @property string info database column
  * @property string name database column
- * @property string studip_object_id database column
  * @property string type database column
  * @property SimpleORMapCollection _children has_many StudipStudyArea
  * @property Institute institute belongs_to Institute