diff --git a/lib/launcher.js b/lib/launcher.js
index 84b5cce16..f0fde7054 100644
--- a/lib/launcher.js
+++ b/lib/launcher.js
@@ -1,16 +1,17 @@
-var Promise = require('bluebird')
-var Jobs = require('qjobs')
+'use strict'
 
-var helper = require('./helper')
-var log = require('./logger').create('launcher')
+const Promise = require('bluebird')
+const Jobs = require('qjobs')
 
-var baseDecorator = require('./launchers/base').decoratorFactory
-var captureTimeoutDecorator = require('./launchers/capture_timeout').decoratorFactory
-var retryDecorator = require('./launchers/retry').decoratorFactory
-var processDecorator = require('./launchers/process').decoratorFactory
+const log = require('./logger').create('launcher')
+
+const baseDecorator = require('./launchers/base').decoratorFactory
+const captureTimeoutDecorator = require('./launchers/capture_timeout').decoratorFactory
+const retryDecorator = require('./launchers/retry').decoratorFactory
+const processDecorator = require('./launchers/process').decoratorFactory
 
 // TODO(vojta): remove once nobody uses it
-var baseBrowserDecoratorFactory = function (
+const baseBrowserDecoratorFactory = function (
   baseLauncherDecorator,
   captureTimeoutLauncherDecorator,
   retryLauncherDecorator,
@@ -25,34 +26,22 @@ var baseBrowserDecoratorFactory = function (
   }
 }
 
-var Launcher = function (server, emitter, injector) {
+function Launcher (server, emitter, injector) {
   this._browsers = []
-  var lastStartTime
-  var self = this
-
-  var getBrowserById = function (id) {
-    for (var i = 0; i < self._browsers.length; i++) {
-      if (self._browsers[i].id === id) {
-        return self._browsers[i]
-      }
-    }
+  let lastStartTime
 
-    return null
-  }
+  const getBrowserById = (id) => this._browsers.find((browser) => browser.id === id)
 
-  this.launchSingle = function (protocol, hostname, port, urlRoot, upstreamProxy, processKillTimeout) {
-    var self = this
-    return function (name) {
-      name = (name + '').trim()
-      if (upstreamProxy) {
-        protocol = upstreamProxy.protocol
-        hostname = upstreamProxy.hostname
-        port = upstreamProxy.port
-        urlRoot = upstreamProxy.path + urlRoot.substr(1)
-      }
-      var url = protocol + '//' + hostname + ':' + port + urlRoot
+  this.launchSingle = (protocol, hostname, port, urlRoot, upstreamProxy, processKillTimeout) => {
+    if (upstreamProxy) {
+      protocol = upstreamProxy.protocol
+      hostname = upstreamProxy.hostname
+      port = upstreamProxy.port
+      urlRoot = upstreamProxy.path + urlRoot.substr(1)
+    }
 
-      var locals = {
+    return (name) => {
+      const locals = {
         id: ['value', Launcher.generateId()],
         name: ['value', name],
         processKillTimeout: ['value', processKillTimeout],
@@ -71,81 +60,53 @@ var Launcher = function (server, emitter, injector) {
       try {
         var browser = injector.createChild([locals], ['launcher:' + name]).get('launcher:' + name)
       } catch (e) {
-        if (e.message.indexOf('No provider for "launcher:' + name + '"') !== -1) {
-          log.error('Cannot load browser "%s": it is not registered! ' +
-            'Perhaps you are missing some plugin?', name)
+        if (e.message.indexOf(`No provider for "launcher:${name}"`) !== -1) {
+          log.error(`Cannot load browser "${name}": it is not registered! Perhaps you are missing some plugin?`)
         } else {
-          log.error('Cannot load browser "%s"!\n  ' + e.stack, name)
+          log.error(`Cannot load browser "${name}"!\n  ` + e.stack)
         }
 
         emitter.emit('load_error', 'launcher', name)
         return
       }
 
-      // TODO(vojta): remove in v1.0 (BC for old launchers)
-      if (!browser.forceKill) {
-        browser.forceKill = function () {
-          var me = this
-          return new Promise(function (resolve) {
-            me.kill(resolve)
-          })
-        }
+      this.jobs.add((args, done) => {
+        log.info(`Starting browser ${browser.displayName || browser.name}`)
 
-        browser.restart = function () {
-          var me = this
-          this.kill(function () {
-            me.start(url)
-          })
-        }
-      }
+        browser.on('browser_process_failure', () => done(browser.error))
 
-      self.jobs.add(function (args, done) {
-        log.info('Starting browser %s', helper.isDefined(browser.displayName) ? browser.displayName : browser.name)
-
-        browser.on('browser_process_failure', function () {
-          done(browser.error)
+        browser.on('done', () => {
+          if (!browser.error && browser.state !== browser.STATE_RESTARTING) {
+            done(null, browser)
+          }
         })
 
-        browser.on('done', function () {
-          // We are not done if there was an error as first the retry takes
-          // place which we catch with `browser_process_failure` if it fails
-          if (browser.error || browser.state === browser.STATE_RESTARTING) return
-
-          done(null, browser)
-        })
-
-        browser.start(url)
+        browser.start(`${protocol}//${hostname}:${port}${urlRoot}`)
       }, [])
 
-      self.jobs.run()
-      self._browsers.push(browser)
+      this.jobs.run()
+      this._browsers.push(browser)
     }
   }
 
-  this.launch = function (names, concurrency) {
+  this.launch = (names, concurrency) => {
     log.info(
       'Launching browser%s %s with %s',
       names.length > 1 ? 's' : '',
       names.join(', '),
-      concurrency === Infinity ? 'unlimited concurrency' : 'concurrency ' + concurrency
+      concurrency === Infinity ? 'unlimited concurrency' : `concurrency ${concurrency}`
     )
-    this.jobs = new Jobs({maxConcurrency: concurrency})
+    this.jobs = new Jobs({ maxConcurrency: concurrency })
 
-    var self = this
     lastStartTime = Date.now()
 
-    if (server.loadErrors.length === 0) {
-      names.forEach(function (name) {
-        injector.invoke(self.launchSingle, self)(name)
-      })
+    if (server.loadErrors.length) {
+      this.jobs.add((args, done) => done(), [])
     } else {
-      // Empty task to ensure `end` is emitted
-      this.jobs.add(function (args, done) {
-        done()
-      }, [])
+      names.forEach((name) => injector.invoke(this.launchSingle, this)(name))
     }
 
-    this.jobs.on('end', function (err) {
+    this.jobs.on('end', (err) => {
       log.debug('Finished all browsers')
 
       if (err) {
@@ -155,7 +116,7 @@ var Launcher = function (server, emitter, injector) {
 
     this.jobs.run()
 
-    return self._browsers
+    return this._browsers
   }
 
   this.launch.$inject = [
@@ -173,76 +134,53 @@ var Launcher = function (server, emitter, injector) {
     'config.processKillTimeout'
   ]
 
-  this.kill = function (id, callback) {
-    var browser = getBrowserById(id)
+  this.kill = (id, callback) => {
     callback = callback || function () {}
+    const browser = getBrowserById(id)
 
-    if (!browser) {
-      process.nextTick(callback)
-      return false
+    if (browser) {
+      browser.forceKill().then(callback)
+      return true
     }
-
-    browser.forceKill().then(callback)
-    return true
+    process.nextTick(callback)
+    return false
   }
 
-  this.restart = function (id) {
-    var browser = getBrowserById(id)
-
-    if (!browser) {
-      return false
+  this.restart = (id) => {
+    const browser = getBrowserById(id)
+    if (browser) {
+      browser.restart()
+      return true
     }
-
-    browser.restart()
-    return true
+    return false
   }
 
-  this.killAll = function (callback) {
+  this.killAll = (callback) => {
+    callback = callback || function () {}
     log.debug('Disconnecting all browsers')
 
-    var remaining = 0
-    var finish = function () {
-      remaining--
-      if (!remaining && callback) {
-        callback()
-      }
-    }
-
-    if (!self._browsers.length) {
+    if (!this._browsers.length) {
       return process.nextTick(callback)
     }
 
-    self._browsers.forEach(function (browser) {
-      remaining++
-      browser.forceKill().then(finish)
-    })
+    Promise.all(
+      this._browsers
+        .map((browser) => browser.forceKill())
+    ).then(callback)
   }
 
-  this.areAllCaptured = function () {
-    return !self._browsers.some(function (browser) {
-      return !browser.isCaptured()
-    })
-  }
+  this.areAllCaptured = () => this._browsers.every((browser) => browser.isCaptured())
 
-  this.markCaptured = function (id) {
-    self._browsers.forEach(function (browser) {
-      if (browser.id === id) {
-        browser.markCaptured()
-        log.debug('%s (id %s) captured in %d secs', browser.name, browser.id,
-          (Date.now() - lastStartTime) / 1000)
-      }
-    })
+  this.markCaptured = (id) => {
+    const browser = getBrowserById(id)
+    browser.markCaptured()
+    log.debug(`${browser.name} (id ${browser.id}) captured in ${(Date.now() - lastStartTime) / 1000} secs`)
   }
 
-  // register events
   emitter.on('exit', this.killAll)
 }
 
 Launcher.$inject = ['server', 'emitter', 'injector']
+Launcher.generateId = () => Math.floor(Math.random() * 100000000).toString()
 
-Launcher.generateId = function () {
-  return '' + Math.floor(Math.random() * 100000000)
-}
-
-// PUBLISH
 exports.Launcher = Launcher
diff --git a/test/unit/launcher.spec.js b/test/unit/launcher.spec.js
index 8b69955d5..d00ffa684 100644
--- a/test/unit/launcher.spec.js
+++ b/test/unit/launcher.spec.js
@@ -1,3 +1,5 @@
+'use strict'
+
 var Promise = require('bluebird')
 var di = require('di')
 
@@ -61,9 +63,7 @@ function ScriptBrowser (id, name, baseBrowserDecorator) {
 describe('launcher', () => {
   // mock out id generator
   var lastGeneratedId = null
-  launcher.Launcher.generateId = () => {
-    return ++lastGeneratedId
-  }
+  launcher.Launcher.generateId = () => ++lastGeneratedId
 
   before(() => {
     Promise.setScheduler((fn) => fn())