diff --git a/smithy-aws-protocol-tests/model/restJson1/http-string-payload.smithy b/smithy-aws-protocol-tests/model/restJson1/http-string-payload.smithy
index 1e6612f458b..8aa1f517b43 100644
--- a/smithy-aws-protocol-tests/model/restJson1/http-string-payload.smithy
+++ b/smithy-aws-protocol-tests/model/restJson1/http-string-payload.smithy
@@ -8,7 +8,7 @@ use smithy.test#httpResponseTests
 @http(uri: "/EnumPayload", method: "POST")
 @httpRequestTests([
     {
-        id: "EnumPayloadRequest",
+        id: "RestJsonEnumPayloadRequest",
         uri: "/EnumPayload",
         body: "enumvalue",
         params: { payload: "enumvalue" },
@@ -18,7 +18,7 @@ use smithy.test#httpResponseTests
 ])
 @httpResponseTests([
     {
-        id: "EnumPayloadResponse",
+        id: "RestJsonEnumPayloadResponse",
         body: "enumvalue",
         params: { payload: "enumvalue" },
         protocol: "aws.protocols#restJson1",
@@ -42,7 +42,7 @@ enum StringEnum {
 @http(uri: "/StringPayload", method: "POST")
 @httpRequestTests([
     {
-        id: "StringPayloadRequest",
+        id: "RestJsonStringPayloadRequest",
         uri: "/StringPayload",
         body: "rawstring",
         params: { payload: "rawstring" },
@@ -52,7 +52,7 @@ enum StringEnum {
 ])
 @httpResponseTests([
     {
-        id: "StringPayloadResponse",
+        id: "RestJsonStringPayloadResponse",
         body: "rawstring",
         params: { payload: "rawstring" },
         protocol: "aws.protocols#restJson1",
diff --git a/smithy-aws-protocol-tests/model/restXml/http-string-payload.smithy b/smithy-aws-protocol-tests/model/restXml/http-string-payload.smithy
new file mode 100644
index 00000000000..851e34066e3
--- /dev/null
+++ b/smithy-aws-protocol-tests/model/restXml/http-string-payload.smithy
@@ -0,0 +1,70 @@
+$version: "2.0"
+
+namespace aws.protocoltests.restxml
+
+use smithy.test#httpRequestTests
+use smithy.test#httpResponseTests
+
+@http(uri: "/EnumPayload", method: "POST")
+@httpRequestTests([
+    {
+        id: "RestXmlEnumPayloadRequest",
+        uri: "/EnumPayload",
+        body: "enumvalue",
+        params: { payload: "enumvalue" },
+        method: "POST",
+        protocol: "aws.protocols#restXml"
+    }
+])
+@httpResponseTests([
+    {
+        id: "RestXmlEnumPayloadResponse",
+        body: "enumvalue",
+        params: { payload: "enumvalue" },
+        protocol: "aws.protocols#restXml",
+        code: 200
+    }
+])
+operation HttpEnumPayload {
+    input: EnumPayloadInput,
+    output: EnumPayloadInput
+}
+
+structure EnumPayloadInput {
+    @httpPayload
+    payload: StringEnum
+}
+
+enum StringEnum {
+    V = "enumvalue"
+}
+
+@http(uri: "/StringPayload", method: "POST")
+@httpRequestTests([
+    {
+        id: "RestXmlStringPayloadRequest",
+        uri: "/StringPayload",
+        body: "rawstring",
+        params: { payload: "rawstring" },
+        method: "POST",
+        protocol: "aws.protocols#restXml"
+    }
+])
+@httpResponseTests([
+    {
+        id: "RestXmlStringPayloadResponse",
+        body: "rawstring",
+        params: { payload: "rawstring" },
+        protocol: "aws.protocols#restXml",
+        code: 200
+    }
+])
+operation HttpStringPayload {
+    input: StringPayloadInput,
+    output: StringPayloadInput
+}
+
+structure StringPayloadInput {
+    @httpPayload
+    payload: String
+}
diff --git a/smithy-aws-protocol-tests/model/restXml/main.smithy b/smithy-aws-protocol-tests/model/restXml/main.smithy
index f0ecc623fa5..3865a2ed397 100644
--- a/smithy-aws-protocol-tests/model/restXml/main.smithy
+++ b/smithy-aws-protocol-tests/model/restXml/main.smithy
@@ -50,6 +50,8 @@ service RestXml {
         HttpPayloadTraits,
         HttpPayloadTraitsWithMediaType,
         HttpPayloadWithStructure,
+        HttpEnumPayload,
+        HttpStringPayload,
         HttpPayloadWithUnion,
         HttpPayloadWithXmlName,
         BodyWithXmlName,