diff --git a/admin/mnet/access_control.php b/admin/mnet/access_control.php
index c8ac7cc81a4..f62875778ea 100644
--- a/admin/mnet/access_control.php
+++ b/admin/mnet/access_control.php
@@ -178,7 +178,7 @@ if (!$acl) {
         }
         $deletecolumn = "<a href=\"?id={$aclrecord->id}&amp;action=delete&amp;sesskey={$USER->sesskey}\">"
                 . get_string('delete') . "</a>";
-        $table->data[] = array ($aclrecord->username, $aclrecord->mnet_host_id, $accesscolumn, $deletecolumn);
+        $table->data[] = array (s($aclrecord->username), $aclrecord->mnet_host_id, $accesscolumn, $deletecolumn);
     }
 }