diff --git a/src/Model/Entity/Payments/ApiUpdateInvoiceRequest.php b/src/Model/Entity/Payments/ApiUpdateInvoiceRequest.php
index 58153f4..577d39a 100644
--- a/src/Model/Entity/Payments/ApiUpdateInvoiceRequest.php
+++ b/src/Model/Entity/Payments/ApiUpdateInvoiceRequest.php
@@ -43,6 +43,14 @@ class ApiUpdateInvoiceRequest
      */
     public $amount;
 
+    /**
+     * @var float
+     *
+     * @JMS\Type("float")
+     * @JMS\SerializedName("discountAmount")
+     */
+    public $discountAmount;
+
     /**
      * @var string
      *