diff --git a/test/e2e/support/world.js b/test/e2e/support/world.js
index 6f82c9a41..b2f30700d 100644
--- a/test/e2e/support/world.js
+++ b/test/e2e/support/world.js
@@ -6,50 +6,52 @@ const mkdirp = require('mkdirp')
 const _ = require('lodash')
 const { setWorldConstructor } = require('cucumber')
 
-function World () {
-  this.proxy = require('./proxy')
-  this.template = _.template(`process.env.CHROME_BIN = require('puppeteer').executablePath(); module.exports = function (config) {\n  config.set(\n    <%= content %>\n  );\n};`)
+class World {
+  constructor () {
+    this.proxy = require('./proxy')
+    this.template = _.template(`process.env.CHROME_BIN = require('puppeteer').executablePath(); module.exports = function (config) {\n  config.set(\n    <%= content %>\n  );\n};`)
 
-  this.configFile = {
-    singleRun: true,
-    reporters: ['dots'],
-    frameworks: ['jasmine'],
-    basePath: __dirname,
-    colors: false,
-    __dirname: __dirname,
-    _resolve: function (name) {
-      return path.resolve(__dirname, '..', 'support', name)
+    this.configFile = {
+      singleRun: true,
+      reporters: ['dots'],
+      frameworks: ['jasmine'],
+      basePath: __dirname,
+      colors: false,
+      __dirname: __dirname,
+      _resolve: (name) => path.resolve(__dirname, '..', 'support', name)
+    }
+
+    this.lastRun = {
+      error: null,
+      stdout: '',
+      stderr: ''
     }
   }
 
-  this.addConfigContent = (function (_this) {
-    return function (content) {
-      if (content == null) {
-        content = ''
-      }
-      return vm.runInNewContext(content, _this.configFile)
+  addConfigContent (content) {
+    if (content == null) {
+      content = ''
     }
-  })(this)
+    return vm.runInNewContext(content, this.configFile)
+  }
 
-  this.writeConfigFile = (function (_this) {
-    return function (dir, file, done) {
-      return mkdirp(dir, 0x1ed, function (err) {
-        let content, hash
-        if (err) {
-          return done(err)
-        }
+  writeConfigFile (dir, file, done) {
+    return mkdirp(dir, 0x1ed, (err) => {
+      let content, hash
+      if (err) {
+        return done(err)
+      }
 
-        delete _this.configFile.__dirname
-        content = _this.generateJS(_this.configFile)
-        hash = hasher('md5').update(content + Math.random()).digest('hex')
-        fs.writeFile(path.join(dir, hash + '.' + file), content, function (err) {
-          done(err, hash)
-        })
+      delete this.configFile.__dirname
+      content = this.generateJS(this.configFile)
+      hash = hasher('md5').update(content + Math.random()).digest('hex')
+      fs.writeFile(path.join(dir, hash + '.' + file), content, (err) => {
+        done(err, hash)
       })
-    }
-  })(this)
+    })
+  }
 
-  this.generateJS = function (config) {
+  generateJS (config) {
     return this.template({
       content: JSON.stringify(Object.assign({}, config, {
         customLaunchers: Object.assign({
@@ -58,12 +60,6 @@ function World () {
       }))
     })
   }
-
-  this.lastRun = {
-    error: null,
-    stdout: '',
-    stderr: ''
-  }
 }
 
 setWorldConstructor(World)