diff --git a/data/web/inc/functions.mailbox.inc.php b/data/web/inc/functions.mailbox.inc.php
index 1e8c2f90..80d6900f 100644
--- a/data/web/inc/functions.mailbox.inc.php
+++ b/data/web/inc/functions.mailbox.inc.php
@@ -3657,7 +3657,7 @@ function mailbox($_action, $_type, $_data = null, $_extra = null) {
             $stmt->execute(array(
               ':username' => $username
             ));
-            $stmt = $pdo->prepare("DELETE FROM `sogo_acl` WHERE `c_object` LIKE '%/" . $username . "/%' OR `c_uid` = :username");
+            $stmt = $pdo->prepare("DELETE FROM `sogo_acl` WHERE `c_object` LIKE '%/" . str_replace('%', '\%', $username) . "/%' OR `c_uid` = :username");
             $stmt->execute(array(
               ':username' => $username
             ));