diff --git a/library/Businessprocess/Web/Form/QuickForm.php b/library/Businessprocess/Web/Form/QuickForm.php
index 451c66f..cb4d287 100644
--- a/library/Businessprocess/Web/Form/QuickForm.php
+++ b/library/Businessprocess/Web/Form/QuickForm.php
@@ -46,7 +46,7 @@ abstract class QuickForm extends QuickBaseForm
     protected $request;
 
     /**
-     * @var Url
+     * @var ?Url
      */
     protected $successUrl;
 
@@ -252,6 +252,10 @@ abstract class QuickForm extends QuickBaseForm
     {
     }
 
+    /**
+     * @param $action string|Url
+     * @return $this
+     */
     public function setAction($action)
     {
         if ($action instanceof Url) {