diff --git a/CRM/Report/Form/Event/ParticipantListing.php b/CRM/Report/Form/Event/ParticipantListing.php
index 7ec5255232525338b68ebddab672e51695e7ef9d..548e10bd0f0c2462cf089ff8aa27c38283f85e6a 100644
--- a/CRM/Report/Form/Event/ParticipantListing.php
+++ b/CRM/Report/Form/Event/ParticipantListing.php
@@ -552,6 +552,10 @@ GROUP BY  cv.label
     }
   }
 
+  function groupBy(){
+    $this->_groupBy = "GROUP BY {$this->_aliases['civicrm_participant']}.id";
+  }
+
   function postProcess() {
 
     // get ready with post process params