diff --git a/source/services/payment-actions/embedded.openrpc.json b/source/services/payment-actions/embedded.openrpc.json
index de4bdf5d1..bb79147d5 100644
--- a/source/services/payment-actions/embedded.openrpc.json
+++ b/source/services/payment-actions/embedded.openrpc.json
@@ -35,6 +35,7 @@
           "oneOf": [
             {
               "type": "object",
+	      	  "maxProperties": 0,
               "description": "Empty acknowledgement confirming acceptance of the requested Payment Authentication extension version."
             },
             {