diff --git a/system/src/Grav/Framework/Form/Interfaces/FormInterface.php b/system/src/Grav/Framework/Form/Interfaces/FormInterface.php
index aecb20aff..6b3c724c5 100644
--- a/system/src/Grav/Framework/Form/Interfaces/FormInterface.php
+++ b/system/src/Grav/Framework/Form/Interfaces/FormInterface.php
@@ -18,7 +18,7 @@ use Psr\Http\Message\UploadedFileInterface;
  * Interface FormInterface
  * @package Grav\Framework\Form
  */
-interface FormInterface
+interface FormInterface extends \Serializable
 {
     /**
      * Get HTML id="..." attribute.