diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index bbb925ca5..e7f4f034c 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -15,4 +15,4 @@ jobs:
           node-version: '20.x'
       - run: npm ci
       - run: npm run build:test
-      - run: npm test
+      - run: npm test -- --workerThreads
diff --git a/tests/setup.ts b/tests/setup.ts
index 4724aebe1..cc09ef157 100644
--- a/tests/setup.ts
+++ b/tests/setup.ts
@@ -1,12 +1,4 @@
 import { Buffer } from 'buffer';
-import fetch, { Headers, Request, Response } from 'node-fetch';
-
-if (!globalThis.fetch) {
-  (globalThis as any).fetch = fetch;
-  (globalThis as any).Headers = Headers;
-  (globalThis as any).Request = Request;
-  (globalThis as any).Response = Response;
-}
 
 if (typeof TextDecoder !== 'undefined') {
   // Monkey patch Text Decoder to workaround https://github.com/vercel/edge-runtime/issues/62