diff --git a/apps/user_ldap/lib/wizard.php b/apps/user_ldap/lib/wizard.php
index f6bc586a7a..54454d2ad2 100644
--- a/apps/user_ldap/lib/wizard.php
+++ b/apps/user_ldap/lib/wizard.php
@@ -889,6 +889,7 @@ class Wizard extends LDAPUtility {
 		if(!$this->ldap->isResource($cr)) {
 			return false;
 		}
+		$lastFilter = null;
 		if(isset($filters[count($filters)-1])) {
 			$lastFilter = $filters[count($filters)-1];
 		}