diff --git a/apps/user_ldap/lib/User_LDAP.php b/apps/user_ldap/lib/User_LDAP.php
index fbdf1cc255132..cca772f5b6ff1 100644
--- a/apps/user_ldap/lib/User_LDAP.php
+++ b/apps/user_ldap/lib/User_LDAP.php
@@ -171,6 +171,7 @@ public function dn2UserName($dn) {
 	public function getLDAPUserByLoginName($loginName) {
 		//find out dn of the user name
 		$attrs = $this->access->userManager->getAttributes();
+		$attrs = array_values(array_filter($attrs)); //filter out empty attributes
 		$users = $this->access->fetchUsersByLoginName($loginName, $attrs);
 		if(count($users) < 1) {
 			throw new NotOnLDAP('No user available for the given login name on ' .