diff --git a/package.json b/package.json
index 23070cceb..3a02c64df 100644
--- a/package.json
+++ b/package.json
@@ -117,6 +117,7 @@
     "gulp-util": "^3.0.7",
     "gulp-watch": "^4.3.5",
     "gulp-zip": "^3.2.0",
+    "isomorphic-fetch": "^2.2.1",
     "jsdom": "^8.1.0",
     "jsdom-global": "^1.7.0",
     "jshint-stylish": "~0.1.5",
diff --git a/test/unit/config-manager-test.js b/test/unit/config-manager-test.js
index 075abbe65..77d431d5f 100644
--- a/test/unit/config-manager-test.js
+++ b/test/unit/config-manager-test.js
@@ -1,8 +1,10 @@
+// polyfill fetch
+global.fetch = global.fetch || require('isomorphic-fetch')
 const assert = require('assert')
 const extend = require('xtend')
 const rp = require('request-promise')
 const nock = require('nock')
-var configManagerGen = require('../lib/mock-config-manager')
+const configManagerGen = require('../lib/mock-config-manager')
 const STORAGE_KEY = 'metamask-persistance-key'
 
 describe('config-manager', function() {