diff --git a/include/auth_session.class.php b/include/auth_session.class.php
index c18708372..af0d79c13 100644
--- a/include/auth_session.class.php
+++ b/include/auth_session.class.php
@@ -48,6 +48,9 @@ class authentication extends auth
 
 	public function checkpassword($username, $passwort)
 	{
+		if($passwort=='')
+			return false;
+
 		if($connect=ldap_connect(LDAP_SERVER))
 		{
 			// bind to ldap connection