diff --git a/db/migrations/5.4.6.1_restore_studip_object_id.php b/db/migrations/5.4.6.1_restore_studip_object_id.php
new file mode 100644
index 0000000000000000000000000000000000000000..b79b93344c5b45aeb322102234b60591764a3fbd
--- /dev/null
+++ b/db/migrations/5.4.6.1_restore_studip_object_id.php
@@ -0,0 +1,26 @@
+<?
+
+final class RestoreStudipObjectId extends Migration
+{
+
+    public function description()
+    {
+        return 'Restores the studip_object_id column for sem_tree';
+    }
+
+    protected function up()
+    {
+        // Add database column for sem_tree institute assignments.
+        DBManager::get()->exec("ALTER TABLE `sem_tree` ADD
+            `studip_object_id` CHAR(32) CHARACTER SET latin1 COLLATE latin1_bin NULL DEFAULT NULL AFTER `name`");
+        // Add index for studip_object_id.
+        DBManager::get()->exec("ALTER TABLE `sem_tree` ADD INDEX `studip_object_id` (`studip_object_id`)");
+    }
+
+    protected function down()
+    {
+        // Remove institute assignments for sem_tree entries.
+        DBManager::get()->exec("ALTER TABLE `sem_tree` DROP `studip_object_id`");
+    }
+
+}
diff --git a/lib/classes/StudipSemTree.class.php b/lib/classes/StudipSemTree.class.php
index 203bec15e389324bb18aa56919bfe993af2cf654..70743ade9a7395a5d0205b7d3e782d643124b703 100644
--- a/lib/classes/StudipSemTree.class.php
+++ b/lib/classes/StudipSemTree.class.php
@@ -76,12 +76,8 @@ class StudipSemTree extends TreeAbstract
         $db = $this->view->get_query("view:SEM_TREE_GET_DATA_NO_ENTRIES");
 
         while ($db->next_record()){
-            $this->tree_data[$db->f("sem_tree_id")] = ['type' => $db->f('type'), "info" => $db->f("info"),"studip_object_id" => $db->f("studip_object_id"), "entries" => 0];
-            if ($db->f("studip_object_id")){
-                $name = $db->f("studip_object_name");
-            } else {
-                $name = $db->f("name");
-            }
+            $this->tree_data[$db->f("sem_tree_id")] = ['type' => $db->f('type'), "info" => $db->f("info"), "entries" => 0];
+            $name = $db->f("name");
             $this->storeItem($db->f("sem_tree_id"), $db->f("parent_id"), $name, $db->f("priority"));
         }
     }
@@ -205,10 +201,8 @@ class StudipSemTree extends TreeAbstract
         if ($item_id == "root")
             return "root";
         $ret_id = $item_id;
-        while (!$this->tree_data[$ret_id]['studip_object_id']){
+        while ($ret_id != "root"){
             $ret_id = $this->tree_data[$ret_id]['parent_id'];
-            if ($ret_id == "root")
-                break;
         }
         return $ret_id;
     }
diff --git a/lib/dbviews/sem_tree.view.php b/lib/dbviews/sem_tree.view.php
index f82767dd1ebec9f264280409f2d0ffece0dbf941..008ee933b0ca00f03b166c56fd80c12d056e2ab4 100644
--- a/lib/dbviews/sem_tree.view.php
+++ b/lib/dbviews/sem_tree.view.php
@@ -36,8 +36,8 @@ $_views['sem_number_sql'] = "INTERVAL(start_time," . join(",",$sem_start_times)
 $_views['sem_number_end_sql'] = "IF(duration_time=-1,-1,INTERVAL(start_time+duration_time," . join(",",$sem_start_times) ."))";
 
 $_views["SEM_TREE_GET_DATA_NO_ENTRIES"] = ["pk"=>"sem_tree_id","temp_table_type"=>"HEAP",
-                            "query"=>"SELECT a.*, c.Name AS studip_object_name
-                             FROM sem_tree a LEFT JOIN Institute c ON (a.studip_object_id = c.Institut_id)
+                            "query"=>"SELECT a.*
+                             FROM sem_tree a
                             ORDER BY priority"];
 $_views["SEM_TREE_GET_ENTRIES"] = ["pk"=>"sem_tree_id","temp_table_type"=>"HEAP",
                             "query" => "SELECT st.sem_tree_id, count(b.Seminar_id) AS entries