diff --git a/inc/drivers_ldap.php b/inc/drivers_ldap.php
index f0c34e14..cdb8e58e 100644
--- a/inc/drivers_ldap.php
+++ b/inc/drivers_ldap.php
@@ -609,7 +609,7 @@ function sync_LDAP_groups(){
         $user->fullname = $group;
       }
 
-      if ($user->displayname == "") {
+      if (! isset($user->displayname) || $user->displayname == "") {
         $user->displayname = $group;
       }