diff --git a/smithy-aws-protocol-tests/model/restJson1/http-checksums.smithy b/smithy-aws-protocol-tests/model/restJson1/http-checksums.smithy
new file mode 100644
index 00000000000..71b5cbfd708
--- /dev/null
+++ b/smithy-aws-protocol-tests/model/restJson1/http-checksums.smithy
@@ -0,0 +1,43 @@
+// This file defines test cases that test HTTP checksum trait(s).
+// See: https://awslabs.github.io/smithy/1.0/spec/core/behavior-traits.html#httpchecksumrequired-trait
+$version: "1.0"
+
+namespace aws.protocoltests.restjson
+
+use aws.protocols#restJson1
+use smithy.test#httpRequestTests
+
+/// This example tests httpChecksumRequired trait
+@httpChecksumRequired
+@http(uri: "/HttpChecksumRequired", method: "POST")
+operation HttpChecksumRequired {
+    input: HttpChecksumRequiredInputOutput,
+    output: HttpChecksumRequiredInputOutput
+}
+
+structure HttpChecksumRequiredInputOutput{
+    foo: String
+}
+
+apply HttpChecksumRequired @httpRequestTests([
+    {
+        id: "RestJsonHttpChecksumRequired",
+        documentation: "Adds Content-MD5 header",
+        protocol: restJson1,
+        method: "POST",
+        uri: "/HttpChecksumRequired",
+        body: """
+        {
+            "foo":"base64 encoded md5 checksum"
+        }
+        """,
+        bodyMediaType: "application/json",
+        headers: {
+            "Content-Type": "application/json",
+            "Content-MD5": "iB0/3YSo7maijL0IGOgA9g=="
+        },
+        params: {
+            foo: "base64 encoded md5 checksum"
+        }
+    }
+])
diff --git a/smithy-aws-protocol-tests/model/restJson1/main.smithy b/smithy-aws-protocol-tests/model/restJson1/main.smithy
index c7e2ff38d5b..18744e02d02 100644
--- a/smithy-aws-protocol-tests/model/restJson1/main.smithy
+++ b/smithy-aws-protocol-tests/model/restJson1/main.smithy
@@ -89,5 +89,8 @@ service RestJson {
 
         // custom endpoints with paths
         HostWithPathOperation,
+
+        // checksum(s)
+        HttpChecksumRequired,
     ]
 }