diff --git a/templates/worker-speedtest/README.md b/templates/worker-speedtest/README.md
index b5361b3746f3..934daa109d26 100644
--- a/templates/worker-speedtest/README.md
+++ b/templates/worker-speedtest/README.md
@@ -4,8 +4,7 @@
 
 Worker for measuring download / upload connection speed from the client side, using the [Performance Timing API](https://w3c.github.io/perf-timing-primer/).
 
-[`index.js`](https://github.com/cloudflare/worker-speedtest-template/blob/master/src/index.js) is the content of the Workers script.
-
+[`index.ts`](https://github.com/cloudflare/workers-sdk/tree/main/templates/worker-speedtest/src/index.ts) is the content of the Workers script.
 _Note:_ when running this as your own worker, your latency measurements may differ a small amount from the [official version](https://speed.cloudflare.com). This is due to the fact that we rely on an internal mechanism to determine the amount of server processing time, which is then subtracted from the measurement.
 
 ## Setup
diff --git a/templates/worker-speedtest/jest.config.json b/templates/worker-speedtest/jest.config.json
index 5d491731bd8e..ba361dc04cf3 100644
--- a/templates/worker-speedtest/jest.config.json
+++ b/templates/worker-speedtest/jest.config.json
@@ -11,8 +11,8 @@
 	"testRegex": "/test/.*\\.(test|spec)\\.(ts|tsx|js)$",
 	"testEnvironment": "miniflare",
 	"testEnvironmentOptions": {
-		"scriptPath": "./src/index.js",
+		"scriptPath": "./src/index.ts",
 		"modules": true
 	},
-	"collectCoverageFrom": ["src/**/*.{js,jsx}"]
+	"collectCoverageFrom": ["src/**/*.{ts,js,jsx}"]
 }
diff --git a/templates/worker-speedtest/package.json b/templates/worker-speedtest/package.json
index e5b2dbc37d35..598e5a605816 100644
--- a/templates/worker-speedtest/package.json
+++ b/templates/worker-speedtest/package.json
@@ -3,8 +3,8 @@
 	"version": "0.0.0",
 	"private": true,
 	"scripts": {
-		"deploy": "wrangler deploy src/index.js",
-		"dev": "wrangler dev src/index.js",
+		"deploy": "wrangler deploy src/index.ts",
+		"dev": "wrangler dev src/index.ts",
 		"test": "jest"
 	},
 	"devDependencies": {
diff --git a/templates/worker-speedtest/src/down.ts b/templates/worker-speedtest/src/down.ts
index e52894c1d2d4..c82cd3bf5cda 100644
--- a/templates/worker-speedtest/src/down.ts
+++ b/templates/worker-speedtest/src/down.ts
@@ -17,7 +17,7 @@ export default async function (request: Request) {
 	res.headers.set('content-type', 'application/octet-stream');
 
 	if (request.cf && request.cf.colo) {
-		res.headers.set('cf-meta-colo', request.cf.colo);
+		res.headers.set('cf-meta-colo', String(request.cf.colo));
 	}
 
 	res.headers.set('access-control-expose-headers', 'cf-meta-colo, cf-meta-request-time');
diff --git a/templates/worker-speedtest/src/index.ts b/templates/worker-speedtest/src/index.ts
index 5921b6c91734..26b3bbb774f4 100644
--- a/templates/worker-speedtest/src/index.ts
+++ b/templates/worker-speedtest/src/index.ts
@@ -1,5 +1,5 @@
-import down from './down.js';
-import up from './up.js';
+import down from './down';
+import up from './up';
 
 export default {
 	async fetch(req: Request) {
diff --git a/templates/worker-speedtest/src/up.ts b/templates/worker-speedtest/src/up.ts
index 8b879451e3ec..e0538161db58 100644
--- a/templates/worker-speedtest/src/up.ts
+++ b/templates/worker-speedtest/src/up.ts
@@ -7,7 +7,7 @@ export default async function (request: Request) {
 	res.headers.set('timing-allow-origin', '*');
 
 	if (request.cf && request.cf.colo) {
-		res.headers.set('cf-meta-colo', request.cf.colo);
+		res.headers.set('cf-meta-colo', String(request.cf.colo));
 	}
 
 	res.headers.set('access-control-expose-headers', 'cf-meta-colo, cf-meta-request-time');
diff --git a/templates/worker-speedtest/test/down.test.ts b/templates/worker-speedtest/test/down.test.ts
index bbe2bfcd5d82..a9da64c31d31 100644
--- a/templates/worker-speedtest/test/down.test.ts
+++ b/templates/worker-speedtest/test/down.test.ts
@@ -5,36 +5,36 @@ async function read(res: Response) {
 }
 
 test('default bytes', async () => {
-	const text = await run().then(read);
+	const text = await run('down').then(read);
 	expect(text.length).toBe(0);
 });
 
 [0, 1, 10, 50, 99].forEach(bytes => {
 	test(`low request bytes :: ${bytes}`, async () => {
-		const text = await run('GET', bytes).then(read);
+		const text = await run('down', 'GET', bytes).then(read);
 		expect(text.length).toEqual(bytes);
 	});
 });
 
 [100, 1e3, 1e6, 1e7].forEach(bytes => {
 	test(`request bytes :: get ${bytes} bytes`, async () => {
-		const text = await run('GET', bytes).then(read);
+		const text = await run('down', 'GET', bytes).then(read);
 		expect(text.length).toEqual(bytes);
 	});
 });
 
 test('max bytes', async () => {
-	const text = await run('GET', Infinity).then(read);
+	const text = await run('down', 'GET', Infinity).then(read);
 	expect(text.length).toEqual(1e8);
 });
 
 test('negative bytes', async () => {
-	const content = await run('GET', -100).then(read);
+	const content = await run('down', 'GET', -100).then(read);
 	expect(content.length).toBe(100);
 });
 
 test('includes request time', async () => {
-	const { headers } = await run();
+	const { headers } = await run('down');
 	const reqTime = headers.get('cf-meta-request-time');
 
 	if (!reqTime) throw new Error('missing request time header');
diff --git a/templates/worker-speedtest/test/helpers.ts b/templates/worker-speedtest/test/helpers.ts
index f5825afca996..2da4adfeeb1a 100644
--- a/templates/worker-speedtest/test/helpers.ts
+++ b/templates/worker-speedtest/test/helpers.ts
@@ -1,10 +1,11 @@
-import worker from '../src/up';
+import worker from '../src/index';
 
 type methods = 'GET' | 'POST';
+type directions = 'up' | 'down';
 
-export async function run(method?: methods, num?: number) {
-	let url = 'https://example.com';
+export async function run(direction: directions, method?: methods, num?: number) {
+	let url = `https://example.com/${direction}`;
 	if (num != null) url += '?bytes=' + num;
 	let req = new Request(url, { method });
-	return worker(req);
+	return worker.fetch(req);
 }
diff --git a/templates/worker-speedtest/test/up.test.ts b/templates/worker-speedtest/test/up.test.ts
index e58982b71748..905c01a33f32 100644
--- a/templates/worker-speedtest/test/up.test.ts
+++ b/templates/worker-speedtest/test/up.test.ts
@@ -5,31 +5,19 @@ async function read(res: Response) {
 }
 
 test('get request', async () => {
-	const res = await run('GET');
+	const res = await run('up', 'GET');
 	expect(await read(res)).toEqual('OK');
 	expect(res.status).toBe(200);
 });
 
 test('empty post request', async () => {
-	const res = await run('POST', 0);
-	expect(await read(res)).toEqual('OK');
-	expect(res.status).toBe(200);
-});
-
-test('small post request', async () => {
-	const res = await run('POST', 10);
-	expect(await read(res)).toEqual('OK');
-	expect(res.status).toBe(200);
-});
-
-test('large post request', async () => {
-	const res = await run('POST', 1e8);
+	const res = await run('up', 'POST');
 	expect(await read(res)).toEqual('OK');
 	expect(res.status).toBe(200);
 });
 
 test('includes request time', async () => {
-	const { headers } = await run('POST');
+	const { headers } = await run('up', 'POST');
 	const reqTime = headers.get('cf-meta-request-time');
 
 	if (!reqTime) throw new Error('missing request time header');