diff --git a/src/Riskified/OrderWebhook/Model/Decision.php b/src/Riskified/OrderWebhook/Model/Decision.php
index fd970a6..9844eed 100644
--- a/src/Riskified/OrderWebhook/Model/Decision.php
+++ b/src/Riskified/OrderWebhook/Model/Decision.php
@@ -24,6 +24,7 @@ class Decision extends AbstractModel {
     protected $_fields = array(
         'id' => 'string',
         'decision' => 'object \DecisionDetails',
-        'payment_details' => 'object \PaymentDetails optional'
+        'payment_details' => 'object \PaymentDetails optional',
+        'gateway' => 'string optional'
     );
-}
\ No newline at end of file
+}