diff --git a/mod/forum/backup/moodle2/backup_forum_activity_task.class.php b/mod/forum/backup/moodle2/backup_forum_activity_task.class.php
index cbff0760307..1fe837b961a 100644
--- a/mod/forum/backup/moodle2/backup_forum_activity_task.class.php
+++ b/mod/forum/backup/moodle2/backup_forum_activity_task.class.php
@@ -71,7 +71,7 @@ class backup_forum_activity_task extends backup_activity_task {
         $content= preg_replace($search, '$@FORUMVIEWBYF*$2@$', $content);
 
         // Link to forum discussion with parent syntax
-        $search="/(".$base."\/mod\/forum\/discuss.php\?d\=)([0-9]+)\&parent\=([0-9]+)/";
+        $search = "/(".$base."\/mod\/forum\/discuss.php\?d\=)([0-9]+)(?:\&|\&)parent\=([0-9]+)/";
         $content= preg_replace($search, '$@FORUMDISCUSSIONVIEWPARENT*$2*$3@$', $content);
 
         // Link to forum discussion with relative syntax