diff --git a/codegen-client-test/model/rest-xml-extras.smithy b/codegen-client-test/model/rest-xml-extras.smithy
index 76a6bbd9fa..cd268634e3 100644
--- a/codegen-client-test/model/rest-xml-extras.smithy
+++ b/codegen-client-test/model/rest-xml-extras.smithy
@@ -10,6 +10,8 @@ use smithy.test#httpRequestTests
 /// A REST XML service that sends XML requests and responses.
 @service(sdkId: "Rest XML Protocol")
 @restXml
+@httpApiKeyAuth(scheme: "Apikey", name: "Authorization", in: "header")
+@auth([httpApiKeyAuth])
 service RestXmlExtras {
     version: "2019-12-16",
     operations: [