diff --git a/index.html b/index.html
index 8a90a5a6..0c6077c0 100644
--- a/index.html
+++ b/index.html
@@ -3087,7 +3087,7 @@ <h2>
           [NewObject]
           Promise&lt;void&gt; complete(optional PaymentComplete result = "unknown");
           [NewObject]
-          Promise&lt;void&gt; retry(PaymentValidationErrors errorFields);
+          Promise&lt;void&gt; retry(optional PaymentValidationErrors errorFields);
 
           attribute EventHandler onpayerdetailchange;
         };