diff --git a/mozilla/webtools/bugzilla/.bzrrev b/mozilla/webtools/bugzilla/.bzrrev
index 55c4f4e1b6c..1fd1d142a6f 100644
--- a/mozilla/webtools/bugzilla/.bzrrev
+++ b/mozilla/webtools/bugzilla/.bzrrev
@@ -1 +1 @@
-7568
\ No newline at end of file
+7569
\ No newline at end of file
diff --git a/mozilla/webtools/bugzilla/Bugzilla/Mailer.pm b/mozilla/webtools/bugzilla/Bugzilla/Mailer.pm
index d4a41b7638d..5ee6fd2eb85 100644
--- a/mozilla/webtools/bugzilla/Bugzilla/Mailer.pm
+++ b/mozilla/webtools/bugzilla/Bugzilla/Mailer.pm
@@ -208,7 +208,9 @@ sub build_thread_marker {
         $threadingmarker = "Message-ID: <bug-$bug_id-$user_id$sitespec>";
     }
     else {
-        $threadingmarker = "In-Reply-To: <bug-$bug_id-$user_id$sitespec>" .
+        my $rand_bits = generate_random_password(10);
+        $threadingmarker = "Message-ID: <bug-$bug_id-$user_id-$rand_bits$sitespec>" .
+                           "\nIn-Reply-To: <bug-$bug_id-$user_id$sitespec>" .
                            "\nReferences: <bug-$bug_id-$user_id$sitespec>";
     }