diff --git a/.eslintrc b/.eslintrc
index d7cb8022e..7fab8f127 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -98,7 +98,7 @@
     "no-obj-calls": 2,
     "no-octal": 2,
     "no-octal-escape": 2,
-    "no-path-concat": 2,
+    "no-path-concat": 1,
     "no-proto": 2,
     "no-redeclare": 2,
     "no-regex-spaces": 2,
diff --git a/app/scripts/contentscript.js b/app/scripts/contentscript.js
index 103ea5348..1eb04059d 100644
--- a/app/scripts/contentscript.js
+++ b/app/scripts/contentscript.js
@@ -5,7 +5,7 @@ const extension = require('./lib/extension')
 
 const fs = require('fs')
 const path = require('path')
-const inpageText = fs.readFileSync(__dirname + '/inpage.js').toString()
+const inpageText = fs.readFileSync(path.join(__dirname + '/inpage.js')).toString()
 
 // Eventually this streaming injection could be replaced with:
 // https://developer.mozilla.org/en-US/docs/Mozilla/Tech/XPCOM/Language_Bindings/Components.utils.exportFunction
diff --git a/app/scripts/lib/extension-instance.js b/app/scripts/lib/extension-instance.js
index e0e7c948b..b9d0ed06d 100644
--- a/app/scripts/lib/extension-instance.js
+++ b/app/scripts/lib/extension-instance.js
@@ -26,7 +26,10 @@ function Extension () {
   const _this = this
 
   apis.forEach(function (api) {
-    _this[api] = chrome ? chrome[api] : window[api] || browser.extension[api]
+    _this[api] = chrome !== undefined && chrome[api] ? chrome[api]
+      : window[api] ? window[api]
+        : browser && browser.extension && browser.extension[api]
+          ? browser.extension[api] : null
   })
 }
 
diff --git a/package.json b/package.json
index 1691f769a..2c264cfd0 100644
--- a/package.json
+++ b/package.json
@@ -5,7 +5,8 @@
   "private": true,
   "scripts": {
     "start": "gulp dev",
-    "test": "mocha --require test/helper.js --compilers js:babel-register --recursive \"test/unit/**/*.js\" && npm run ci",
+    "test": "npm run fastTest && npm run ci",
+    "fastTest": "mocha --require test/helper.js --compilers js:babel-register --recursive \"test/unit/**/*.js\"",
     "watch": "mocha watch --compilers js:babel-register --recursive \"test/unit/**/*.js\"",
     "ui": "node development/genStates.js && beefy ui-dev.js:bundle.js --live --open --index=./development/index.html --cwd ./",
     "mock": "beefy mock-dev.js:bundle.js --live --open --index=./development/index.html --cwd ./",
diff --git a/test/unit/extension-test.js b/test/unit/extension-test.js
index 0a03a3b97..6b695e835 100644
--- a/test/unit/extension-test.js
+++ b/test/unit/extension-test.js
@@ -1,6 +1,8 @@
 var assert = require('assert')
 var sinon = require('sinon')
 const ethUtil = require('ethereumjs-util')
+GLOBAL.chrome = {}
+GLOBAL.browser = {}
 
 var path = require('path')
 var Extension = require(path.join(__dirname, '..', '..', 'app', 'scripts', 'lib', 'extension-instance.js'))
@@ -11,7 +13,7 @@ describe('extension', function() {
     let extension
 
     beforeEach(function() {
-      window.chrome = {
+      GLOBAL.chrome = {
         alarms: 'foo'
       }
       extension = new Extension()
@@ -24,13 +26,20 @@ describe('extension', function() {
 
   describe('without chrome global', function() {
     let extension
+    let realWindow
 
     beforeEach(function() {
-      window.chrome = undefined
-      window.alarms = 'foo'
+      realWindow = window
+      window = GLOBAL
+      GLOBAL.chrome = undefined
+      GLOBAL.alarms = 'foo'
       extension = new Extension()
     })
 
+    after(function() {
+      window = realWindow
+    })
+
     it('should use the global apis', function() {
       assert.equal(extension.alarms, 'foo')
     })