diff --git a/modules/monitoring/library/Monitoring/Backend/Ido/Query/HostdowntimeQuery.php b/modules/monitoring/library/Monitoring/Backend/Ido/Query/HostdowntimeQuery.php
index 95b61198c..0a8fdf664 100644
--- a/modules/monitoring/library/Monitoring/Backend/Ido/Query/HostdowntimeQuery.php
+++ b/modules/monitoring/library/Monitoring/Backend/Ido/Query/HostdowntimeQuery.php
@@ -13,6 +13,16 @@ class HostdowntimeQuery extends IdoQuery
      */
     protected $allowCustomVars = true;
 
+    /**
+     * {@inheritdoc}
+     */
+    protected $groupBase = array('downtimes' => array('sd.scheduleddowntime_id', 'ho.object_id'));
+
+    /**
+     * {@inheritdoc}
+     */
+    protected $groupOrigin = array('hostgroups', 'servicegroups', 'services');
+
     /**
      * {@inheritdoc}
      */
@@ -171,28 +181,4 @@ class HostdowntimeQuery extends IdoQuery
             array()
         );
     }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getGroup()
-    {
-        $group = array();
-        if ($this->hasJoinedVirtualTable('hostgroups') || $this->hasJoinedVirtualTable('servicegroups') || $this->hasJoinedVirtualTable('services')) {
-            $group = array('sd.scheduleddowntime_id', 'ho.object_id');
-            if ($this->hasJoinedVirtualTable('hosts')) {
-                $group[] = 'h.host_id';
-            }
-
-            if ($this->hasJoinedVirtualTable('hoststatus')) {
-                $group[] = 'hs.hoststatus_id';
-            }
-
-            if ($this->hasJoinedVirtualTable('instances')) {
-                $group[] = 'i.instance_id';
-            }
-        }
-
-        return $group;
-    }
 }