diff --git a/include/class.ticket.php b/include/class.ticket.php
index f269cb7937c96e7d0e470ead736a8bdf79e13396..47b1713c56729266597b7fd5fd94a8e6c3ef789b 100644
--- a/include/class.ticket.php
+++ b/include/class.ticket.php
@@ -2884,7 +2884,10 @@ implements RestrictedAccess, Threadable {
             ->filter(array('number' => $number));
 
         if ($email)
-            $query->filter(array('user__emails__address' => $email));
+            $query->filter(Q::any(array(
+                'user__emails__address' => $email,
+                'thread__collaborators__user__emails__address' => $email
+            )));
 
 
         if (!$ticket) {