diff --git a/src/http/fetch-polyfill.ts b/src/http/fetch-polyfill.ts
index b03f853..848866e 100644
--- a/src/http/fetch-polyfill.ts
+++ b/src/http/fetch-polyfill.ts
@@ -5,8 +5,11 @@ import {
   Response,
 } from 'node-fetch';
 
-// Registering Fetch as a glboal polyfill
-(global as any).fetch = nodeFetch;
-(global as any).Request = Request;
-(global as any).Headers = Headers;
-(global as any).Response = Response;
+const globalThis = global as any;
+
+if (!globalThis.fetch) {
+  globalThis.fetch = nodeFetch;
+  globalThis.Request = Request;
+  globalThis.Headers = Headers;
+  globalThis.Response = Response;
+}
diff --git a/test/integration/fetch-api.ts b/test/integration/fetch-api.ts
index 8e5273c..64fa232 100644
--- a/test/integration/fetch-api.ts
+++ b/test/integration/fetch-api.ts
@@ -20,7 +20,7 @@ describe('Using the fetch api', () => {
 
   it('should also work when passing a Request object', async () => {
 
-    const request = new Request('?foo=bar');
+    const request = new Request('http://localhost:3000/?foo=bar');
     const response = await hal2.fetch(request);
     expect(response).to.have.property('status');
     expect(response.status).to.eql(200);