diff --git a/readme.md b/readme.md
index af813fe..eb18609 100644
--- a/readme.md
+++ b/readme.md
@@ -1,6 +1,6 @@
 # swork
 
-[![npm](https://img.shields.io/npm/v/swork)](https://www.npmjs.com/package/swork) [![travis ci](https://travis-ci.org/justin-lee-collins/swork.svg?branch=master)](https://travis-ci.org/justin-lee-collins/swork.svg?branch=master)[![Coverage Status](https://coveralls.io/repos/github/justin-lee-collins/swork/badge.svg?branch=master)](https://coveralls.io/github/justin-lee-collins/swork?branch=master) [![download](https://img.shields.io/npm/dw/swork)](https://img.shields.io/npm/dw/swork)
+[![npm](https://img.shields.io/npm/v/swork)](https://www.npmjs.com/package/swork) [![travis ci](https://travis-ci.org/justin-lee-collins/swork.svg?branch=master)](https://travis-ci.org/justin-lee-collins/swork.svg?branch=master) [![Coverage Status](https://coveralls.io/repos/github/justin-lee-collins/swork/badge.svg?branch=master)](https://coveralls.io/github/justin-lee-collins/swork?branch=master) [![download](https://img.shields.io/npm/dw/swork)](https://img.shields.io/npm/dw/swork)
 
 swork is a service worker building framework intended to be a robust foundation for service worker applications. TypeScript and async functions are central to its implementation enabling increased productivity, reduced error rate and the removal of callbacks. Swork is not bundled with any middleware.
 
diff --git a/tests/mock-helper.ts b/tests/mock-helper.ts
index 19c6566..3d14de2 100644
--- a/tests/mock-helper.ts
+++ b/tests/mock-helper.ts
@@ -6,6 +6,8 @@ import * as Request from "service-worker-mock/models/Request";
 // @ts-ignore 
 import * as Response from "service-worker-mock/models/Response";
 
+declare var global: any;
+
 export function mockInit() {
     Object.assign(global, makeServiceWorkerEnv(), {
         fetch: (request: RequestInfo) => {