diff --git a/smithy-aws-protocol-tests/model/awsJson1_0/unions.smithy b/smithy-aws-protocol-tests/model/awsJson1_0/unions.smithy
index 1085397e263..a397a348800 100644
--- a/smithy-aws-protocol-tests/model/awsJson1_0/unions.smithy
+++ b/smithy-aws-protocol-tests/model/awsJson1_0/unions.smithy
@@ -57,8 +57,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonRpc10.JsonUnions",
         },
         params: {
-            "contents": {
-                "stringValue": "foo"
+            contents: {
+                stringValue: "foo"
             }
         }
     },
@@ -80,8 +80,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonRpc10.JsonUnions",
         },
         params: {
-            "contents": {
-                "booleanValue": true
+            contents: {
+                booleanValue: true
             }
         }
     },
@@ -103,8 +103,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonRpc10.JsonUnions",
         },
         params: {
-            "contents": {
-                "numberValue": 1
+            contents: {
+                numberValue: 1
             }
         }
     },
@@ -126,8 +126,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonRpc10.JsonUnions",
         },
         params: {
-            "contents": {
-                "blobValue": "foo"
+            contents: {
+                blobValue: "foo"
             }
         }
     },
@@ -149,8 +149,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonRpc10.JsonUnions",
         },
         params: {
-            "contents": {
-                "timestampValue": 1398796238
+            contents: {
+                timestampValue: 1398796238
             }
         }
     },
@@ -172,8 +172,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonRpc10.JsonUnions",
         },
         params: {
-            "contents": {
-                "enumValue": "Foo"
+            contents: {
+                enumValue: "Foo"
             }
         }
     },
@@ -195,8 +195,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonRpc10.JsonUnions",
         },
         params: {
-            "contents": {
-                "listValue": ["foo", "bar"]
+            contents: {
+                listValue: ["foo", "bar"]
             }
         }
     },
@@ -221,10 +221,10 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonRpc10.JsonUnions",
         },
         params: {
-            "contents": {
-                "mapValue": {
-                    "foo": "bar",
-                    "spam": "eggs",
+            contents: {
+                mapValue: {
+                    foo: "bar",
+                    spam: "eggs",
                 }
             }
         }
@@ -249,9 +249,9 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonRpc10.JsonUnions",
         },
         params: {
-            "contents": {
-                "structureValue": {
-                    "hi": "hello",
+            contents: {
+                structureValue: {
+                    hi: "hello",
                 }
             }
         }
@@ -275,8 +275,8 @@ apply JsonUnions @httpResponseTests([
             "Content-Type": "application/x-amz-json-1.0",
         },
         params: {
-            "contents": {
-                "stringValue": "foo"
+            contents: {
+                stringValue: "foo"
             }
         }
     },
@@ -296,8 +296,8 @@ apply JsonUnions @httpResponseTests([
             "Content-Type": "application/x-amz-json-1.0",
         },
         params: {
-            "contents": {
-                "booleanValue": true
+            contents: {
+                booleanValue: true
             }
         }
     },
@@ -317,8 +317,8 @@ apply JsonUnions @httpResponseTests([
             "Content-Type": "application/x-amz-json-1.0",
         },
         params: {
-            "contents": {
-                "numberValue": 1
+            contents: {
+                numberValue: 1
             }
         }
     },
@@ -338,8 +338,8 @@ apply JsonUnions @httpResponseTests([
             "Content-Type": "application/x-amz-json-1.0",
         },
         params: {
-            "contents": {
-                "blobValue": "foo"
+            contents: {
+                blobValue: "foo"
             }
         }
     },
@@ -359,8 +359,8 @@ apply JsonUnions @httpResponseTests([
             "Content-Type": "application/x-amz-json-1.0",
         },
         params: {
-            "contents": {
-                "timestampValue": 1398796238
+            contents: {
+                timestampValue: 1398796238
             }
         }
     },
@@ -380,8 +380,8 @@ apply JsonUnions @httpResponseTests([
             "Content-Type": "application/x-amz-json-1.0",
         },
         params: {
-            "contents": {
-                "enumValue": "Foo"
+            contents: {
+                enumValue: "Foo"
             }
         }
     },
@@ -401,8 +401,8 @@ apply JsonUnions @httpResponseTests([
             "Content-Type": "application/x-amz-json-1.0",
         },
         params: {
-            "contents": {
-                "listValue": ["foo", "bar"]
+            contents: {
+                listValue: ["foo", "bar"]
             }
         }
     },
@@ -425,10 +425,10 @@ apply JsonUnions @httpResponseTests([
             "Content-Type": "application/x-amz-json-1.0",
         },
         params: {
-            "contents": {
-                "mapValue": {
-                    "foo": "bar",
-                    "spam": "eggs",
+            contents: {
+                mapValue: {
+                    foo: "bar",
+                    spam: "eggs",
                 }
             }
         }
@@ -451,9 +451,9 @@ apply JsonUnions @httpResponseTests([
             "Content-Type": "application/x-amz-json-1.0",
         },
         params: {
-            "contents": {
-                "structureValue": {
-                    "hi": "hello",
+            contents: {
+                structureValue: {
+                    hi: "hello",
                 }
             }
         }
diff --git a/smithy-aws-protocol-tests/model/awsJson1_1/unions.smithy b/smithy-aws-protocol-tests/model/awsJson1_1/unions.smithy
index d3f9435ea14..6fa72b309c9 100644
--- a/smithy-aws-protocol-tests/model/awsJson1_1/unions.smithy
+++ b/smithy-aws-protocol-tests/model/awsJson1_1/unions.smithy
@@ -57,8 +57,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonProtocol.JsonUnions",
         },
         params: {
-            "contents": {
-                "stringValue": "foo"
+            contents: {
+                stringValue: "foo"
             }
         }
     },
@@ -80,8 +80,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonProtocol.JsonUnions",
         },
         params: {
-            "contents": {
-                "booleanValue": true
+            contents: {
+                booleanValue: true
             }
         }
     },
@@ -103,8 +103,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonProtocol.JsonUnions",
         },
         params: {
-            "contents": {
-                "numberValue": 1
+            contents: {
+                numberValue: 1
             }
         }
     },
@@ -126,8 +126,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonProtocol.JsonUnions",
         },
         params: {
-            "contents": {
-                "blobValue": "foo"
+            contents: {
+                blobValue: "foo"
             }
         }
     },
@@ -149,8 +149,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonProtocol.JsonUnions",
         },
         params: {
-            "contents": {
-                "timestampValue": 1398796238
+            contents: {
+                timestampValue: 1398796238
             }
         }
     },
@@ -172,8 +172,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonProtocol.JsonUnions",
         },
         params: {
-            "contents": {
-                "enumValue": "Foo"
+            contents: {
+                enumValue: "Foo"
             }
         }
     },
@@ -195,8 +195,8 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonProtocol.JsonUnions",
         },
         params: {
-            "contents": {
-                "listValue": ["foo", "bar"]
+            contents: {
+                listValue: ["foo", "bar"]
             }
         }
     },
@@ -221,10 +221,10 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonProtocol.JsonUnions",
         },
         params: {
-            "contents": {
-                "mapValue": {
-                    "foo": "bar",
-                    "spam": "eggs",
+            contents: {
+                mapValue: {
+                    foo: "bar",
+                    spam: "eggs",
                 }
             }
         }
@@ -249,9 +249,9 @@ apply JsonUnions @httpRequestTests([
             "X-Amz-Target": "JsonProtocol.JsonUnions",
         },
         params: {
-            "contents": {
-                "structureValue": {
-                    "hi": "hello",
+            contents: {
+                structureValue: {
+                    hi: "hello",
                 }
             }
         }
@@ -273,8 +273,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/x-amz-json-1.1"},
         params: {
-            "contents": {
-                "stringValue": "foo"
+            contents: {
+                stringValue: "foo"
             }
         }
     },
@@ -292,8 +292,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/x-amz-json-1.1"},
         params: {
-            "contents": {
-                "booleanValue": true
+            contents: {
+                booleanValue: true
             }
         }
     },
@@ -311,8 +311,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/x-amz-json-1.1"},
         params: {
-            "contents": {
-                "numberValue": 1
+            contents: {
+                numberValue: 1
             }
         }
     },
@@ -330,8 +330,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/x-amz-json-1.1"},
         params: {
-            "contents": {
-                "blobValue": "foo"
+            contents: {
+                blobValue: "foo"
             }
         }
     },
@@ -349,8 +349,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/x-amz-json-1.1"},
         params: {
-            "contents": {
-                "timestampValue": 1398796238
+            contents: {
+                timestampValue: 1398796238
             }
         }
     },
@@ -368,8 +368,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/x-amz-json-1.1"},
         params: {
-            "contents": {
-                "enumValue": "Foo"
+            contents: {
+                enumValue: "Foo"
             }
         }
     },
@@ -387,8 +387,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/x-amz-json-1.1"},
         params: {
-            "contents": {
-                "listValue": ["foo", "bar"]
+            contents: {
+                listValue: ["foo", "bar"]
             }
         }
     },
@@ -409,10 +409,10 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/x-amz-json-1.1"},
         params: {
-            "contents": {
-                "mapValue": {
-                    "foo": "bar",
-                    "spam": "eggs"
+            contents: {
+                mapValue: {
+                    foo: "bar",
+                    spam: "eggs"
                 }
             }
         }
@@ -433,9 +433,9 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/x-amz-json-1.1"},
         params: {
-            "contents": {
-                "structureValue": {
-                    "hi": "hello",
+            contents: {
+                structureValue: {
+                    hi: "hello",
                 }
             }
         }
diff --git a/smithy-aws-protocol-tests/model/restJson1/unions.smithy b/smithy-aws-protocol-tests/model/restJson1/unions.smithy
index 1ee40020436..619f03d9822 100644
--- a/smithy-aws-protocol-tests/model/restJson1/unions.smithy
+++ b/smithy-aws-protocol-tests/model/restJson1/unions.smithy
@@ -55,8 +55,8 @@ apply JsonUnions @httpRequestTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "stringValue": "foo"
+            contents: {
+                stringValue: "foo"
             }
         }
     },
@@ -75,8 +75,8 @@ apply JsonUnions @httpRequestTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "booleanValue": true
+            contents: {
+                booleanValue: true
             }
         }
     },
@@ -95,8 +95,8 @@ apply JsonUnions @httpRequestTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "numberValue": 1
+            contents: {
+                numberValue: 1
             }
         }
     },
@@ -115,8 +115,8 @@ apply JsonUnions @httpRequestTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "blobValue": "foo"
+            contents: {
+                blobValue: "foo"
             }
         }
     },
@@ -135,8 +135,8 @@ apply JsonUnions @httpRequestTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "timestampValue": 1398796238
+            contents: {
+                timestampValue: 1398796238
             }
         }
     },
@@ -155,8 +155,8 @@ apply JsonUnions @httpRequestTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "enumValue": "Foo"
+            contents: {
+                enumValue: "Foo"
             }
         }
     },
@@ -175,8 +175,8 @@ apply JsonUnions @httpRequestTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "listValue": ["foo", "bar"]
+            contents: {
+                listValue: ["foo", "bar"]
             }
         }
     },
@@ -198,10 +198,10 @@ apply JsonUnions @httpRequestTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "mapValue": {
-                    "foo": "bar",
-                    "spam": "eggs",
+            contents: {
+                mapValue: {
+                    foo: "bar",
+                    spam: "eggs",
                 }
             }
         }
@@ -223,9 +223,9 @@ apply JsonUnions @httpRequestTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "structureValue": {
-                    "hi": "hello",
+            contents: {
+                structureValue: {
+                    hi: "hello",
                 }
             }
         }
@@ -247,8 +247,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "stringValue": "foo"
+            contents: {
+                stringValue: "foo"
             }
         }
     },
@@ -266,8 +266,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "booleanValue": true
+            contents: {
+                booleanValue: true
             }
         }
     },
@@ -285,8 +285,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "numberValue": 1
+            contents: {
+                numberValue: 1
             }
         }
     },
@@ -304,8 +304,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "blobValue": "foo"
+            contents: {
+                blobValue: "foo"
             }
         }
     },
@@ -323,8 +323,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "timestampValue": 1398796238
+            contents: {
+                timestampValue: 1398796238
             }
         }
     },
@@ -342,8 +342,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "enumValue": "Foo"
+            contents: {
+                enumValue: "Foo"
             }
         }
     },
@@ -361,8 +361,8 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "listValue": ["foo", "bar"]
+            contents: {
+                listValue: ["foo", "bar"]
             }
         }
     },
@@ -383,10 +383,10 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "mapValue": {
-                    "foo": "bar",
-                    "spam": "eggs",
+            contents: {
+                mapValue: {
+                    foo: "bar",
+                    spam: "eggs",
                 }
             }
         }
@@ -407,9 +407,9 @@ apply JsonUnions @httpResponseTests([
         bodyMediaType: "application/json",
         headers: {"Content-Type": "application/json"},
         params: {
-            "contents": {
-                "structureValue": {
-                    "hi": "hello",
+            contents: {
+                structureValue: {
+                    hi: "hello",
                 }
             }
         }