diff --git a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
index ebf52a91e0..221a4735c4 100644
--- a/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
+++ b/codegen-server/src/main/kotlin/software/amazon/smithy/rust/codegen/server/smithy/generators/protocol/ServerProtocolTestGenerator.kt
@@ -52,6 +52,7 @@ import software.amazon.smithy.rust.codegen.client.util.inputShape
 import software.amazon.smithy.rust.codegen.client.util.isStreaming
 import software.amazon.smithy.rust.codegen.client.util.orNull
 import software.amazon.smithy.rust.codegen.client.util.outputShape
+import software.amazon.smithy.rust.codegen.client.util.toPascalCase
 import software.amazon.smithy.rust.codegen.client.util.toSnakeCase
 import software.amazon.smithy.rust.codegen.server.smithy.ServerCargoDependency
 import software.amazon.smithy.rust.codegen.server.smithy.ServerRuntimeType
@@ -75,6 +76,7 @@ class ServerProtocolTestGenerator(
     private val symbolProvider = coreCodegenContext.symbolProvider
     private val operationIndex = OperationIndex.of(coreCodegenContext.model)
 
+    private val serviceName = coreCodegenContext.serviceShape.id.name.toPascalCase()
     private val operations = TopDownIndex.of(coreCodegenContext.model).getContainedOperations(coreCodegenContext.serviceShape).sortedBy { it.id }
 
     private val operationInputOutputTypes = operations.associateWith {
@@ -357,6 +359,8 @@ class ServerProtocolTestGenerator(
             rust("/* test case disabled for this protocol (not yet supported) */")
             return
         }
+
+        // Test against original `OperationRegistryBuilder`.
         with(httpRequestTestCase) {
             renderHttpRequest(uri, method, headers, body.orNull(), queryParams, host.orNull())
         }
@@ -364,6 +368,14 @@ class ServerProtocolTestGenerator(
             checkRequest(operationShape, operationSymbol, httpRequestTestCase, this)
         }
 
+        // Test against new service builder.
+        with(httpRequestTestCase) {
+            renderHttpRequest(uri, method, headers, body.orNull(), queryParams, host.orNull())
+        }
+        if (protocolSupport.requestBodyDeserialization) {
+            checkRequest2(operationShape, operationSymbol, httpRequestTestCase, this)
+        }
+
         // Explicitly warn if the test case defined parameters that we aren't doing anything with
         with(httpRequestTestCase) {
             if (authScheme.isPresent) {
@@ -495,11 +507,34 @@ class ServerProtocolTestGenerator(
         }
     }
 
-    private fun checkRequest(operationShape: OperationShape, operationSymbol: Symbol, httpRequestTestCase: HttpRequestTestCase, rustWriter: RustWriter) {
+    /** Returns the body of the request test. */
+    private fun checkRequestHandler(operationShape: OperationShape, httpRequestTestCase: HttpRequestTestCase) = writable {
         val inputShape = operationShape.inputShape(coreCodegenContext.model)
         val outputShape = operationShape.outputShape(coreCodegenContext.model)
 
+        // Construct expected request.
+        withBlock("let expected = ", ";") {
+            instantiator.render(this, inputShape, httpRequestTestCase.params)
+        }
+
+        checkRequestParams(inputShape, this)
+
+        // Construct a dummy response.
+        withBlock("let response = ", ";") {
+            instantiator.render(this, outputShape, Node.objectNode(), Instantiator.defaultContext().copy(defaultsForRequiredFields = true))
+        }
+
+        if (operationShape.errors.isEmpty()) {
+            write("response")
+        } else {
+            write("Ok(response)")
+        }
+    }
+
+    /** Checks the request using the `OperationRegistryBuilder`. */
+    private fun checkRequest(operationShape: OperationShape, operationSymbol: Symbol, httpRequestTestCase: HttpRequestTestCase, rustWriter: RustWriter) {
         val (inputT, outputT) = operationInputOutputTypes[operationShape]!!
+
         rustWriter.withBlock(
             """
             super::$PROTOCOL_TEST_HELPER_MODULE_NAME::build_router_and_make_request(
@@ -509,29 +544,33 @@ class ServerProtocolTestGenerator(
                     builder.${operationShape.toName()}((|input| Box::pin(async move {
             """,
 
-            "})) as super::$PROTOCOL_TEST_HELPER_MODULE_NAME::Fun<$inputT, $outputT>)}).await",
+            "})) as super::$PROTOCOL_TEST_HELPER_MODULE_NAME::Fun<$inputT, $outputT>)}).await;",
 
         ) {
-            // Construct expected request.
-            rustWriter.withBlock("let expected = ", ";") {
-                instantiator.render(this, inputShape, httpRequestTestCase.params)
-            }
-
-            checkRequestParams(inputShape, rustWriter)
-
-            // Construct a dummy response.
-            rustWriter.withBlock("let response = ", ";") {
-                instantiator.render(this, outputShape, Node.objectNode(), Instantiator.defaultContext().copy(defaultsForRequiredFields = true))
-            }
-
-            if (operationShape.errors.isEmpty()) {
-                rustWriter.write("response")
-            } else {
-                rustWriter.write("Ok(response)")
-            }
+            checkRequestHandler(operationShape, httpRequestTestCase)()
         }
     }
 
+    /** Checks the request using the new service builder. */
+    private fun checkRequest2(operationShape: OperationShape, operationSymbol: Symbol, httpRequestTestCase: HttpRequestTestCase, rustWriter: RustWriter) {
+        val (inputT, outputT) = operationInputOutputTypes[operationShape]!!
+        val operationName = RustReservedWords.escapeIfNeeded(operationSymbol.name.toSnakeCase())
+        rustWriter.rustTemplate(
+            """
+            let service = crate::service::$serviceName::unchecked_builder()
+                .$operationName(|input: $inputT| async move {
+                    #{Body:W}
+                })
+                .build::<#{Hyper}::body::Body>();
+            let http_response = #{Tower}::ServiceExt::oneshot(service, http_request)
+                .await
+                .expect("unable to make an HTTP request");
+            """,
+            "Body" to checkRequestHandler(operationShape, httpRequestTestCase),
+            *codegenScope,
+        )
+    }
+
     private fun checkRequestParams(inputShape: StructureShape, rustWriter: RustWriter) {
         if (inputShape.hasStreamingMember(model)) {
             // A streaming shape does not implement `PartialEq`, so we have to iterate over the input shape's members