diff --git a/.circleci/config.yml b/.circleci/config.yml
index 1154d4230..d8999a521 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -12,46 +12,62 @@ jobs:
       - checkout
       - restore_cache:
           keys:
-            - v1-npm-{{ .Branch }}-{{ checksum "package.json" }}
-            - v1-npm-master-{{ checksum "package.json" }}
+            - v3-npm-{{ .Branch }}-{{ checksum "package.json" }}
+            - v3-npm-master-{{ checksum "package.json" }}
       - run:
           name: Install dependencies
           command: |
               npm config set strict-ssl false
-              # Avoid downloading chromium unnecessarily
-              npm config set ignore-scripts true
-              npm install
-              npm config set ignore-scripts false
+              # puppeteer install script throws syntax errors for Node v4
+              # https://github.com/GoogleChrome/puppeteer/blob/f19e2ade0d4859435422131905e932abe3db199c/install.js#L66
+              if node --version | grep -q '^v4'; then
+                npm config set ignore-scripts true
+                npm install
+                npm config set ignore-scripts false
+              else
+                npm install
+              fi
+
+              # install latest chrome unstable version
+              if node --version | grep -q '^v6'; then
+                wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -
+                echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list
+                apt-get update
+                apt-get install -y --no-install-recommends google-chrome-unstable
+              fi
       - run:
           name: Pre-Test
           # ESLint only supports Node >=4
           command: |
-              NODE_VERSION=$(node --version)
-              if [[ ${NODE_VERSION:0:3} == "v6." ]]; then
+              if node --version | grep -q '^v6'; then
                 npm run lint;
+                npm run test-headless -- --chrome $(which google-chrome-unstable) --allow-chrome-as-root;
+                npm run test-webworker -- --chrome $(which google-chrome-unstable) --allow-chrome-as-root;
               fi
       - run:
           name: Test
           command: npm run test-node
       - save_cache:
-          key: v1-npm-{{ .Branch }}-{{ checksum "package.json" }}
+          key: v3-npm-{{ .Branch }}-{{ checksum "package.json" }}
           paths:
             - node_modules
 
   node-4:
     <<: *common-build
     docker:
-      - image: node:4
+      - image: node:4-alpine
 
   node-6:
     <<: *common-build
     docker:
-      - image: node:6-alpine
+      - image: node:6
 
   node-8:
     <<: *common-build
     docker:
-      - image: node:8
+      - image: node:8-alpine
+    environment:
+        PUPPETEER_SKIP_CHROMIUM_DOWNLOAD: true
 
 workflows:
   version: 2
diff --git a/package.json b/package.json
index e2999fe9f..55d338a5c 100644
--- a/package.json
+++ b/package.json
@@ -55,7 +55,7 @@
     "lint-staged": "^4.0.0",
     "markdownlint-cli": "^0.4.0",
     "mocha": "^4.0.0",
-    "mochify": "^5.0.0",
+    "mochify": "^5.1.0",
     "mochify-istanbul": "^2.4.1",
     "native-promise-only": "^0.8.1",
     "npm-run-all": "^4.0.2",