diff --git a/lib/plugins/authad/auth.php b/lib/plugins/authad/auth.php
index 7e2d902bdcb85ba47032bc1af6a06d8aa71bfd65..a0fec7b52b890d494d8927aa58be0b3f01d84df0 100644
--- a/lib/plugins/authad/auth.php
+++ b/lib/plugins/authad/auth.php
@@ -336,7 +336,7 @@ class auth_plugin_authad extends DokuWiki_Auth_Plugin {
         $adldap = $this->_adldap(null);
         if(!$adldap) return false;
 
-        if($this->users === null) {
+        if(!$this->users) {
             //get info for given user
             $result = $adldap->user()->all();
             if (!$result) return array();