diff --git a/mod/forum/classes/local/vaults/discussion_list.php b/mod/forum/classes/local/vaults/discussion_list.php
index 41866143d3c..e099a671ae0 100644
--- a/mod/forum/classes/local/vaults/discussion_list.php
+++ b/mod/forum/classes/local/vaults/discussion_list.php
@@ -350,7 +350,7 @@ class discussion_list extends db_table_vault {
             $favouritesort .= ", {$favalias}.itemtype DESC";
         }
 
-        return "{$alias}.pinned DESC $favouritesort , {$keyfield} {$direction}";
+        return "{$alias}.pinned DESC $favouritesort , {$keyfield} {$direction}, {$alias}.id {$direction}";
     }
 
     /**