diff --git a/smithy-aws-protocol-tests/model/awsJson1_0/content-type.smithy b/smithy-aws-protocol-tests/model/awsJson1_0/content-type.smithy
new file mode 100644
index 00000000000..db83af8a0ab
--- /dev/null
+++ b/smithy-aws-protocol-tests/model/awsJson1_0/content-type.smithy
@@ -0,0 +1,44 @@
+// This file defines test cases that test Content-Type headers.
+
+$version: "2.0"
+
+namespace aws.protocoltests.json10
+
+use aws.protocols#awsJson1_0
+use smithy.test#httpRequestTests
+use smithy.test#httpResponseTests
+
+/// The example tests how servers must support requests
+/// containing a `Content-Type` header with parameters.
+operation ContentTypeParameters {
+    input: ContentTypeParametersInput,
+    output: ContentTypeParametersOutput
+}
+
+apply ContentTypeParameters @httpRequestTests([
+    {
+        id: "AwsJson10MustSupportParametersInContentType",
+        documentation: "A server should ignore parameters added to the content type",
+        protocol: awsJson1_0,
+        method: "POST",
+        headers: {
+            "Content-Type": "application/x-amz-json-1.0; charset=utf-8",
+            "X-Amz-Target": "JsonRpc10.ContentTypeParameters",
+        },
+        uri: "/",
+        body: "{\"value\":5}",
+        bodyMediaType: "application/json",
+        params: {
+            value: 5,
+        },
+        appliesTo: "server"
+    }
+])
+
+@input
+structure ContentTypeParametersInput {
+    value: Integer,
+}
+
+@output
+structure ContentTypeParametersOutput {}
diff --git a/smithy-aws-protocol-tests/model/awsJson1_0/main.smithy b/smithy-aws-protocol-tests/model/awsJson1_0/main.smithy
index 091a5c93bfc..6204e414ebf 100644
--- a/smithy-aws-protocol-tests/model/awsJson1_0/main.smithy
+++ b/smithy-aws-protocol-tests/model/awsJson1_0/main.smithy
@@ -35,6 +35,9 @@ service JsonRpc10 {
         // requestCompression trait tests
         PutWithContentEncoding,
 
+        // Content-Type header tests
+        ContentTypeParameters,
+
         OperationWithDefaults,
         OperationWithRequiredMembers,
         OperationWithNestedStructure
diff --git a/smithy-aws-protocol-tests/model/awsJson1_1/content-type.smithy b/smithy-aws-protocol-tests/model/awsJson1_1/content-type.smithy
new file mode 100644
index 00000000000..4b1159e0c95
--- /dev/null
+++ b/smithy-aws-protocol-tests/model/awsJson1_1/content-type.smithy
@@ -0,0 +1,44 @@
+// This file defines test cases that test Content-Type headers.
+
+$version: "2.0"
+
+namespace aws.protocoltests.json
+
+use aws.protocols#awsJson1_1
+use smithy.test#httpRequestTests
+use smithy.test#httpResponseTests
+
+/// The example tests how servers must support requests
+/// containing a `Content-Type` header with parameters.
+operation ContentTypeParameters {
+    input: ContentTypeParametersInput,
+    output: ContentTypeParametersOutput
+}
+
+apply ContentTypeParameters @httpRequestTests([
+    {
+        id: "AwsJson11MustSupportParametersInContentType",
+        documentation: "A server should ignore parameters added to the content type",
+        protocol: awsJson1_1,
+        method: "POST",
+        headers: {
+            "Content-Type": "application/x-amz-json-1.1; charset=utf-8",
+            "X-Amz-Target": "JsonProtocol.ContentTypeParameters",
+        },
+        uri: "/",
+        body: "{\"value\":5}",
+        bodyMediaType: "application/json",
+        params: {
+            value: 5,
+        },
+        appliesTo: "server"
+    }
+])
+
+@input
+structure ContentTypeParametersInput {
+    value: Integer,
+}
+
+@output
+structure ContentTypeParametersOutput {}
diff --git a/smithy-aws-protocol-tests/model/awsJson1_1/main.smithy b/smithy-aws-protocol-tests/model/awsJson1_1/main.smithy
index 9503e7df7ad..fcd1c29c925 100644
--- a/smithy-aws-protocol-tests/model/awsJson1_1/main.smithy
+++ b/smithy-aws-protocol-tests/model/awsJson1_1/main.smithy
@@ -44,6 +44,9 @@ service JsonProtocol {
 
         // requestCompression trait tests
         PutWithContentEncoding
+
+        // Content-Type header tests
+        ContentTypeParameters,
     ],
 }
 
diff --git a/smithy-aws-protocol-tests/model/restJson1/content-type.smithy b/smithy-aws-protocol-tests/model/restJson1/content-type.smithy
new file mode 100644
index 00000000000..f003441f07e
--- /dev/null
+++ b/smithy-aws-protocol-tests/model/restJson1/content-type.smithy
@@ -0,0 +1,41 @@
+// This file defines test cases that test Content-Type headers.
+
+$version: "2.0"
+
+namespace aws.protocoltests.restjson
+
+use aws.protocols#restJson1
+use aws.protocoltests.shared#DateTime
+use smithy.test#httpRequestTests
+
+/// The example tests how servers must support requests
+/// containing a `Content-Type` header with parameters.
+@http(uri: "/ContentTypeParameters", method: "POST")
+operation ContentTypeParameters {
+    input: ContentTypeParametersInput,
+    output: ContentTypeParametersOutput,
+}
+
+apply ContentTypeParameters @httpRequestTests([
+    {
+        id: "RestJsonMustSupportParametersInContentType",
+        documentation: "A server should ignore parameters added to the content type",
+        uri: "/ContentTypeParameters",
+        method: "POST",
+        protocol: "aws.protocols#restJson1",
+        body: "{\"value\":5}",
+        headers: { "Content-Type": "application/json; charset=utf-8" },
+        params: {
+            value: 5,
+        },
+        appliesTo: "server",
+    },
+])
+
+@input
+structure ContentTypeParametersInput {
+    value: Integer,
+}
+
+@output
+structure ContentTypeParametersOutput {}
diff --git a/smithy-aws-protocol-tests/model/restJson1/main.smithy b/smithy-aws-protocol-tests/model/restJson1/main.smithy
index 10c35886db2..2a414502b46 100644
--- a/smithy-aws-protocol-tests/model/restJson1/main.smithy
+++ b/smithy-aws-protocol-tests/model/restJson1/main.smithy
@@ -151,7 +151,10 @@ service RestJson {
         FractionalSeconds,
 
         // requestCompression trait tests
-        PutWithContentEncoding
+        PutWithContentEncoding,
+
+        // Content-Type header tests
+        ContentTypeParameters,
 
         // defaults
         OperationWithDefaults
diff --git a/smithy-aws-protocol-tests/model/restXml/content-type.smithy b/smithy-aws-protocol-tests/model/restXml/content-type.smithy
new file mode 100644
index 00000000000..4dc9c578e13
--- /dev/null
+++ b/smithy-aws-protocol-tests/model/restXml/content-type.smithy
@@ -0,0 +1,44 @@
+// This file defines test cases that test Content-Type headers.
+
+$version: "2.0"
+
+namespace aws.protocoltests.restxml
+
+use aws.protocols#restXml
+use aws.protocoltests.shared#DateTime
+use smithy.test#httpRequestTests
+
+/// The example tests how servers must support requests
+/// containing a `Content-Type` header with parameters.
+@http(uri: "/ContentTypeParameters", method: "PUT")
+operation ContentTypeParameters {
+    input: ContentTypeParametersInput,
+    output: ContentTypeParametersOutput
+}
+
+apply ContentTypeParameters @httpRequestTests([
+    {
+        id: "RestXmlMustSupportParametersInContentType",
+        documentation: "A server should ignore parameters added to the content type",
+        protocol: restXml,
+        method: "PUT",
+        headers: {
+            "Content-Type": "application/xml; charset=utf-8"
+        },
+        uri: "/ContentTypeParameters",
+        body: "<ContentTypeParametersInput><value>5</value></ContentTypeParametersInput>",
+        bodyMediaType: "application/xml",
+        params: {
+            value: 5,
+        },
+        appliesTo: "server"
+    }
+])
+
+@input
+structure ContentTypeParametersInput {
+    value: Integer,
+}
+
+@output
+structure ContentTypeParametersOutput {}
diff --git a/smithy-aws-protocol-tests/model/restXml/main.smithy b/smithy-aws-protocol-tests/model/restXml/main.smithy
index 348eb303c82..3841d31295b 100644
--- a/smithy-aws-protocol-tests/model/restXml/main.smithy
+++ b/smithy-aws-protocol-tests/model/restXml/main.smithy
@@ -105,6 +105,9 @@ service RestXml {
         FractionalSeconds,
 
         // requestCompression trait tests
-        PutWithContentEncoding
+        PutWithContentEncoding,
+
+        // Content-Type header tests
+        ContentTypeParameters,
     ]
 }