diff --git a/packages/nice-grpc-client-middleware-devtools/jest.config.js b/packages/nice-grpc-client-middleware-devtools/jest.config.js
index d4c74235..5bb07079 100644
--- a/packages/nice-grpc-client-middleware-devtools/jest.config.js
+++ b/packages/nice-grpc-client-middleware-devtools/jest.config.js
@@ -1,6 +1,6 @@
 /** @type {import('@jest/types').Config.GlobalConfig} */
 module.exports = {
-  testPathIgnorePatterns: ['/node_modules/', '/lib/'],
+  testPathIgnorePatterns: ['/node_modules/', '/lib/', '/fixtures/'],
   preset: 'ts-jest',
   testEnvironment: 'node',
   testTimeout: 15000,
@@ -9,4 +9,9 @@ module.exports = {
   coverageDirectory: 'coverage',
   coverageReporters: ['lcov', 'text'],
   coveragePathIgnorePatterns: ['/node_modules/', '/lib/'],
+  globals: {
+    window: {
+      postMessage: () => ({}),
+    },
+  },
 };
diff --git a/packages/nice-grpc-client-middleware-devtools/package.json b/packages/nice-grpc-client-middleware-devtools/package.json
index 952e3ff0..afb4d27f 100644
--- a/packages/nice-grpc-client-middleware-devtools/package.json
+++ b/packages/nice-grpc-client-middleware-devtools/package.json
@@ -16,8 +16,10 @@
     "test": "jest",
     "build": "tsc -P tsconfig.build.json",
     "prepublishOnly": "npm run clean && npm run build && npm test",
-    "build:proto": "grpc_tools_node_protoc --plugin=protoc-gen-grpc=./node_modules/.bin/grpc_tools_node_protoc_plugin --plugin=protoc-gen-ts=./node_modules/.bin/protoc-gen-ts --js_out=import_style=commonjs,binary:./fixtures --ts_out=grpc_js:./fixtures --grpc_out=grpc_js:./fixtures -I fixtures fixtures/*.proto",
-    "prepare": "npm run build:proto"
+    "prepare:proto:grpc-js": "mkdirp ./fixtures/grpc-js && grpc_tools_node_protoc --plugin=protoc-gen-grpc=./node_modules/.bin/grpc_tools_node_protoc_plugin --plugin=protoc-gen-ts=./node_modules/.bin/protoc-gen-ts --js_out=import_style=commonjs,binary:./fixtures/grpc-js --ts_out=grpc_js:./fixtures/grpc-js --grpc_out=grpc_js:./fixtures/grpc-js -I fixtures fixtures/*.proto",
+    "prepare:proto:ts-proto": "mkdirp ./fixtures/ts-proto && grpc_tools_node_protoc --ts_proto_out=./fixtures/ts-proto --ts_proto_opt=outputServices=nice-grpc,outputServices=generic-definitions,useExactTypes=false,esModuleInterop=true -I fixtures fixtures/*.proto",
+    "prepare:proto": "npm run prepare:proto:grpc-js && npm run prepare:proto:ts-proto",
+    "prepare": "npm run prepare:proto"
   },
   "author": "Sebastian Halder",
   "license": "MIT",
diff --git a/packages/nice-grpc-client-middleware-devtools/src/index.test.ts b/packages/nice-grpc-client-middleware-devtools/src/index.test.ts
index f87cee07..cd9182f2 100644
--- a/packages/nice-grpc-client-middleware-devtools/src/index.test.ts
+++ b/packages/nice-grpc-client-middleware-devtools/src/index.test.ts
@@ -8,7 +8,120 @@ import {
   Status,
 } from 'nice-grpc';
 import {devtoolsLoggingMiddleware} from '.';
-import {TestService} from '../fixtures/test_grpc_pb';
-import {TestRequest, TestResponse} from '../fixtures/test_pb';
+import {TestService} from '../fixtures/grpc-js/test_grpc_pb';
+import {
+  TestDefinition,
+  TestRequest as TestRequestTS,
+} from '../fixtures/ts-proto/test';
+import {
+  TestRequest as TestRequestJS,
+  TestResponse as TestResponseJS,
+} from '../fixtures/grpc-js/test_pb';
+
+function throwUnimplemented(): never {
+  throw new ServerError(Status.UNIMPLEMENTED, '');
+}
+
+let windowSpy: jest.SpyInstance;
+let postMessageMock: jest.Mock;
+
+beforeEach(() => {
+  postMessageMock = jest.fn();
+  windowSpy = jest.spyOn(window, 'postMessage');
+  windowSpy.mockImplementation(postMessageMock);
+});
+
+afterEach(() => {
+  windowSpy.mockRestore();
+});
+
+describe('devtools', () => {
+  test('grpc-js logs unary calls', async () => {
+    const server = createServer();
+
+    server.add(TestService, {
+      async testUnary(request: TestRequestJS, {signal}) {
+        return new TestResponseJS();
+      },
+      testServerStream: throwUnimplemented,
+      testClientStream: throwUnimplemented,
+      testBidiStream: throwUnimplemented,
+    });
+
+    const port = await server.listen('localhost:0');
+
+    const channel = createChannel(`localhost:${port}`);
+    const client = createClientFactory()
+      .use(devtoolsLoggingMiddleware)
+      .create(TestService, channel);
+
+    const req = new TestRequestJS();
+    req.setId('test-id');
+
+    const promise = client.testUnary(req);
+
+    await expect(promise).resolves.toEqual(new TestResponseJS());
+    await expect(postMessageMock).toHaveBeenCalledTimes(1);
+    await expect(postMessageMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        request: {
+          id: 'test-id',
+        },
+        response: {
+          id: '',
+        },
+        methodType: 'unary',
+        method: '/nice_grpc.test.Test/TestUnary',
+      }),
+      '*',
+    );
+
+    channel.close();
+
+    await server.shutdown();
+  });
+
+  test('ts-proto logs unary calls', async () => {
+    const server = createServer();
+
+    server.add(TestService, {
+      async testUnary(request: TestRequestJS, {signal}) {
+        return new TestResponseJS();
+      },
+      testServerStream: throwUnimplemented,
+      testClientStream: throwUnimplemented,
+      testBidiStream: throwUnimplemented,
+    });
+
+    const port = await server.listen('localhost:0');
+
+    const channel = createChannel(`localhost:${port}`);
+    const client = createClientFactory()
+      .use(devtoolsLoggingMiddleware)
+      .create(TestDefinition, channel);
+
+    const req: TestRequestTS = {id: 'test-id'};
+
+    const promise = client.testUnary(req);
+
+    await expect(promise).resolves.toEqual({id: ''});
+    await expect(postMessageMock).toHaveBeenCalledTimes(1);
+    await expect(postMessageMock).toHaveBeenCalledWith(
+      expect.objectContaining({
+        request: {
+          id: 'test-id',
+        },
+        response: {
+          id: '',
+        },
+        methodType: 'unary',
+        method: '/nice_grpc.test.Test/TestUnary',
+      }),
+      '*',
+    );
+
+    channel.close();
 
-// TODO: Can this middleware be tested?
\ No newline at end of file
+    await server.shutdown();
+  });
+});