diff --git a/src/Model/Entity/Payments/ApiUpdateInvoiceRequest.php b/src/Model/Entity/Payments/ApiUpdateInvoiceRequest.php
index 58153f485..577d39ad8 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
      *
diff --git a/tests/src/ResourceGroup/PaymentsTest.php b/tests/src/ResourceGroup/PaymentsTest.php
index 8cd2d414a..8186a28d2 100644
--- a/tests/src/ResourceGroup/PaymentsTest.php
+++ b/tests/src/ResourceGroup/PaymentsTest.php
@@ -99,6 +99,7 @@ public function testUpdateInvoice(): void
         $invoiceRequest->paymentId   = 'd6458333-fff3-4fd0-9b23-4e6344451f8e';
         $invoiceRequest->invoiceUuid = '5b1b2e9d-b7f1-48f4-acb9-4bfce04b30cf';
         $invoiceRequest->invoiceUrl  = 'https://example.com/newUrl';
+        $invoiceRequest->discountAmount = 20.0;
 
         $request = new PaymentUpdateInvoiceRequest($invoiceRequest);