diff --git a/index.js b/index.js
index bf9b966424..4259593dc9 100644
--- a/index.js
+++ b/index.js
@@ -4,155 +4,267 @@
 // We have to replace the error codes and make them coherent.
 // We also have to use InterruptError s instead of AbortError s.
 // The Error messages might be improved as well.
-// TODO: Rewrite this to classes
-const net = require('net')
-const util = require('util')
-const utils = require('./lib/utils')
 const Queue = require('denque')
 const EventEmitter = require('events')
-const Errors = require('redis-errors')
-const connect = require('./lib/connect')
+const net = require('net')
 const Commands = require('redis-commands')
+const Errors = require('redis-errors')
+const Command = require('./lib/command')
 const addCommand = require('./lib/commands')
+const connect = require('./lib/connect')
 const unifyOptions = require('./lib/createClient')
+const debug = require('./lib/debug')
+const flushAndError = require('./lib/flushAndError')
 const Multi = require('./lib/multi')
-const normalizeAndWriteCommand = require('./lib/writeCommands')
 const offlineCommand = require('./lib/offlineCommand')
+const utils = require('./lib/utils')
+const normalizeAndWriteCommand = require('./lib/writeCommands')
+const noop = function () {}
 
 // Attention: The second parameter might be removed at will and is not officially supported.
 // Do not rely on this
-function RedisClient (options, stream) {
-  // Copy the options so they are not mutated
-  options = utils.clone(options)
-  EventEmitter.call(this)
-  const cnxOptions = {}
-  /* istanbul ignore next: travis does not work with stunnel atm. Therefore the tls tests are skipped on travis */
-  for (const tlsOption in options.tls) {
-    if (options.tls.hasOwnProperty(tlsOption)) {
-      cnxOptions[tlsOption] = options.tls[tlsOption]
-      // Copy the tls options into the general options to make sure the address is set right
-      if (tlsOption === 'port' || tlsOption === 'host' || tlsOption === 'path' || tlsOption === 'family') {
-        options[tlsOption] = options.tls[tlsOption]
+class RedisClient extends EventEmitter {
+  /**
+   * Creates an instance of RedisClient.
+   * @param {object} options
+   * @param {any} [stream]
+   *
+   * @memberof RedisClient
+   */
+  constructor (options, stream) {
+    super()
+    // Copy the options so they are not mutated
+    options = utils.clone(options)
+    const cnxOptions = {}
+    /* istanbul ignore next: travis does not work with stunnel atm. Therefore the tls tests are skipped on travis */
+    for (const tlsOption in options.tls) {
+      if (options.tls.hasOwnProperty(tlsOption)) {
+        cnxOptions[tlsOption] = options.tls[tlsOption]
+        // Copy the tls options into the general options to make sure the address is set right
+        if (tlsOption === 'port' || tlsOption === 'host' || tlsOption === 'path' || tlsOption === 'family') {
+          options[tlsOption] = options.tls[tlsOption]
+        }
       }
     }
-  }
-  if (stream) {
-    // The stream from the outside is used so no connection from this side is triggered but from the server this client should talk to
-    // Reconnect etc won't work with this. This requires monkey patching to work, so it is not officially supported
-    options.stream = stream
-    this.address = '"Private stream"'
-  } else if (options.path) {
-    cnxOptions.path = options.path
-    this.address = options.path
-  } else {
-    cnxOptions.port = +options.port || 6379
-    cnxOptions.host = options.host || '127.0.0.1'
-    cnxOptions.family = (!options.family && net.isIP(cnxOptions.host)) || (options.family === 'IPv6' ? 6 : 4)
-    this.address = `${cnxOptions.host}:${cnxOptions.port}`
+    if (stream) {
+      // The stream from the outside is used so no connection from this side is triggered but from the server this client should talk to
+      // Reconnect etc won't work with this. This requires monkey patching to work, so it is not officially supported
+      options.stream = stream
+      this.address = '"Private stream"'
+    } else if (options.path) {
+      cnxOptions.path = options.path
+      this.address = options.path
+    } else {
+      cnxOptions.port = +options.port || 6379
+      cnxOptions.host = options.host || '127.0.0.1'
+      cnxOptions.family = (!options.family && net.isIP(cnxOptions.host)) || (options.family === 'IPv6' ? 6 : 4)
+      this.address = `${cnxOptions.host}:${cnxOptions.port}`
+    }
+
+    this.connectionOptions = cnxOptions
+    this.connectionId = RedisClient.connectionId++
+    this.connected = false
+    if (options.socketKeepalive === undefined) {
+      options.socketKeepalive = true
+    }
+    for (const command in options.renameCommands) {
+      if (options.renameCommands.hasOwnProperty(command)) {
+        options.renameCommands[command.toLowerCase()] = options.renameCommands[command]
+      }
+    }
+    options.returnBuffers = !!options.returnBuffers
+    options.detectBuffers = !!options.detectBuffers
+    // Override the detectBuffers setting if returnBuffers is active and print a warning
+    if (options.returnBuffers && options.detectBuffers) {
+      process.nextTick(
+        utils.warn,
+        this,
+        'WARNING: You activated returnBuffers and detectBuffers at the same time. The return value is always going to be a buffer.'
+      )
+      options.detectBuffers = false
+    }
+    this.shouldBuffer = false
+    this.commandQueue = new Queue() // Holds sent commands to de-pipeline them
+    this.offlineQueue = new Queue() // Holds commands issued but not able to be sent
+    this._pipelineQueue = new Queue() // Holds all pipelined commands
+    // Only used as timeout until redis has to be connected to redis until throwing an connection error
+    this.connectTimeout = +options.connectTimeout || 60000 // 60 * 1000 ms
+    this.enableOfflineQueue = options.enableOfflineQueue !== false
+    this.pubSubMode = 0
+    this.subscriptionSet = {}
+    this.monitoring = false
+    this.messageBuffers = false
+    this.closing = false
+    this.serverInfo = {}
+    this.authPass = options.authPass || options.password
+    this.selectedDb = options.db // Save the selected db here, used when reconnecting
+    this.oldState = null
+    this._strCache = ''
+    this._pipeline = false
+    this.subCommandsLeft = 0
+    this.renameCommands = options.renameCommands || {}
+    this.timesConnected = 0
+    this.buffers = options.returnBuffers || options.detectBuffers
+    this.options = options
+    this._multi = false
+    this.reply = 'ON' // Returning replies is the default
+    this.retryStrategy = options.retryStrategy || function (options) {
+      if (options.attempt > 100) {
+        return
+      }
+      // reconnect after
+      return Math.min(options.attempt * 100, 3000)
+    }
+    this.retryStrategyProvided = !!options.retryStrategy
+    this.subscribeChannels = []
+    utils.setReconnectDefaults(this)
+    // Init parser and connect
+    connect(this)
+    this.on('newListener', function (event) {
+      if ((event === 'messageBuffer' || event === 'pmessageBuffer') && !this.buffers && !this.messageBuffers) {
+        this.messageBuffers = true
+        this._replyParser.setReturnBuffers(true)
+      }
+    })
   }
 
-  this.connectionOptions = cnxOptions
-  this.connectionId = RedisClient.connectionId++
-  this.connected = false
-  if (options.socketKeepalive === undefined) {
-    options.socketKeepalive = true
-  }
-  for (const command in options.renameCommands) {
-    if (options.renameCommands.hasOwnProperty(command)) {
-      options.renameCommands[command.toLowerCase()] = options.renameCommands[command]
+  // Do not call internalSendCommand directly, if you are not absolutely certain it handles everything properly
+  // e.g. monitor / info does not work with internalSendCommand only
+  internalSendCommand (commandObj) {
+    if (this.ready === false || this._stream.writable === false) {
+      // Handle offline commands right away
+      offlineCommand(this, commandObj)
+      return commandObj.promise
     }
-  }
-  options.returnBuffers = !!options.returnBuffers
-  options.detectBuffers = !!options.detectBuffers
-  // Override the detectBuffers setting if returnBuffers is active and print a warning
-  if (options.returnBuffers && options.detectBuffers) {
-    process.nextTick(
-      utils.warn,
-      this,
-      'WARNING: You activated returnBuffers and detectBuffers at the same time. The return value is always going to be a buffer.'
-    )
-    options.detectBuffers = false
-  }
-  this.shouldBuffer = false
-  this.commandQueue = new Queue() // Holds sent commands to de-pipeline them
-  this.offlineQueue = new Queue() // Holds commands issued but not able to be sent
-  this._pipelineQueue = new Queue() // Holds all pipelined commands
-  // Only used as timeout until redis has to be connected to redis until throwing an connection error
-  this.connectTimeout = +options.connectTimeout || 60000 // 60 * 1000 ms
-  this.enableOfflineQueue = options.enableOfflineQueue !== false
-  this.pubSubMode = 0
-  this.subscriptionSet = {}
-  this.monitoring = false
-  this.messageBuffers = false
-  this.closing = false
-  this.serverInfo = {}
-  this.authPass = options.authPass || options.password
-  this.selectedDb = options.db // Save the selected db here, used when reconnecting
-  this.oldState = null
-  this._strCache = ''
-  this._pipeline = false
-  this.subCommandsLeft = 0
-  this.renameCommands = options.renameCommands || {}
-  this.timesConnected = 0
-  this.buffers = options.returnBuffers || options.detectBuffers
-  this.options = options
-  this._multi = false
-  this.reply = 'ON' // Returning replies is the default
-  this.retryStrategy = options.retryStrategy || function (options) {
-    if (options.attempt > 100) {
-      return
-    }
-    // reconnect after
-    return Math.min(options.attempt * 100, 3000)
-  }
-  this.retryStrategyProvided = !!options.retryStrategy
-  this.subscribeChannels = []
-  utils.setReconnectDefaults(this)
-  // Init parser and connect
-  connect(this)
-  this.on('newListener', function (event) {
-    if ((event === 'messageBuffer' || event === 'pmessageBuffer') && !this.buffers && !this.messageBuffers) {
-      this.messageBuffers = true
-      this._replyParser.setReturnBuffers(true)
-    }
-  })
-}
-util.inherits(RedisClient, EventEmitter)
 
-RedisClient.connectionId = 0
+    normalizeAndWriteCommand(this, commandObj)
 
-// Do not call internalSendCommand directly, if you are not absolutely certain it handles everything properly
-// e.g. monitor / info does not work with internalSendCommand only
-RedisClient.prototype.internalSendCommand = function (commandObj) {
-  if (this.ready === false || this._stream.writable === false) {
-    // Handle offline commands right away
-    offlineCommand(this, commandObj)
+    if (commandObj.callOnWrite) {
+      commandObj.callOnWrite()
+    }
+    // Handle `CLIENT REPLY ON|OFF|SKIP`
+    // This has to be checked after callOnWrite
+    /* istanbul ignore else: TODO: Remove this as soon as we test Redis 3.2 on travis */
+    if (this.reply === 'ON') {
+      this.commandQueue.push(commandObj)
+    } else {
+      // Do not expect a reply
+      // Does this work in combination with the pub sub mode?
+      utils.replyInOrder(this, commandObj.callback, null, undefined, this.commandQueue)
+      if (this.reply === 'SKIP') {
+        this.reply = 'SKIP_ONE_MORE'
+      } else if (this.reply === 'SKIP_ONE_MORE') {
+        this.reply = 'ON'
+      }
+    }
     return commandObj.promise
   }
 
-  normalizeAndWriteCommand(this, commandObj)
+  // Redirect calls to the appropriate function and use to send arbitrary / not supported commands
+  sendCommand (command, args) {
+    // Throw to fail early instead of relying in order in this case
+    if (typeof command !== 'string') {
+      throw new TypeError(`Wrong input type "${command !== null && command !== undefined ? command.constructor.name : command}" for command name`)
+    }
+    if (!Array.isArray(args)) {
+      if (args === undefined || args === null) {
+        args = []
+      } else {
+        throw new TypeError(`Wrong input type "${args.constructor.name}" for args`)
+      }
+    }
 
-  if (commandObj.callOnWrite) {
-    commandObj.callOnWrite()
+    // Using the raw multi command is only possible with this function
+    // If the command is not yet added to the client, the internal function should be called right away
+    // Otherwise we need to redirect the calls to make sure the internal functions don't get skipped
+    // The internal functions could actually be used for any non hooked function
+    // but this might change from time to time and at the moment there's no good way to distinguish them
+    // from each other, so let's just do it do it this way for the time being
+    if (command === 'multi' || typeof this[command] !== 'function') {
+      return this.internalSendCommand(new Command(command, args))
+    }
+    return this[command].apply(this, args)
   }
-  // Handle `CLIENT REPLY ON|OFF|SKIP`
-  // This has to be checked after callOnWrite
-  /* istanbul ignore else: TODO: Remove this as soon as we test Redis 3.2 on travis */
-  if (this.reply === 'ON') {
-    this.commandQueue.push(commandObj)
-  } else {
-    // Do not expect a reply
-    // Does this work in combination with the pub sub mode?
-    utils.replyInOrder(this, commandObj.callback, null, undefined, this.commandQueue)
-    if (this.reply === 'SKIP') {
-      this.reply = 'SKIP_ONE_MORE'
-    } else if (this.reply === 'SKIP_ONE_MORE') {
-      this.reply = 'ON'
+
+  end (flush) {
+    if (typeof flush !== 'boolean') {
+      throw new TypeError('You must call "end" with the flush argument.')
+    }
+
+    // Flush queue if wanted
+    if (flush) {
+      flushAndError(this, 'Connection forcefully ended and command aborted.', 'NR_CLOSED')
+    }
+    // Clear retryTimer
+    if (this.retryTimer) {
+      clearTimeout(this.retryTimer)
+      this.retryTimer = null
+    }
+    this._stream.removeAllListeners()
+    this._stream.on('error', noop)
+    this.connected = false
+    this.ready = false
+    this.closing = true
+    return this._stream.destroySoon()
+  }
+
+  unref () {
+    if (this.connected) {
+      debug('Unref\'ing the socket connection')
+      this._stream.unref()
+    } else {
+      debug('Not connected yet, will unref later')
+      this.once('connect', function () {
+        this.unref()
+      })
     }
   }
-  return commandObj.promise
+
+  // TODO: promisify this
+  duplicate (options, callback) {
+    if (typeof options === 'function') {
+      callback = options
+      options = null
+    }
+    const existingOptions = utils.clone(this.options)
+    options = utils.clone(options)
+    for (const elem in options) {
+      if (options.hasOwnProperty(elem)) {
+        existingOptions[elem] = options[elem]
+      }
+    }
+    const client = new RedisClient(existingOptions)
+    client.selectedDb = this.selectedDb
+    if (typeof callback === 'function') {
+      const errorListener = function (err) {
+        callback(err)
+        client.end(true)
+      }
+      const readyListener = function () {
+        callback(null, client)
+        client.removeAllListeners(errorListener)
+      }
+      client.once('ready', readyListener)
+      client.once('error', errorListener)
+      return client
+    }
+    return client
+  }
+
+  // Note: this overrides a native function!
+  multi (args) {
+    return new Multi(this, 'multi', args)
+  }
+
+  // Note: This is not a native function but is still handled as a individual command as it behaves just the same as multi
+  batch (args) {
+    return new Multi(this, 'batch', args)
+  }
+
 }
 
+RedisClient.connectionId = 0
+
 Commands.list.forEach((name) => addCommand(RedisClient.prototype, Multi.prototype, name))
 
 module.exports = {
@@ -172,4 +284,3 @@ module.exports = {
 // Add all redis commands / nodeRedis api to the client
 // TODO: Change the way this is included...
 require('./lib/individualCommands')
-require('./lib/extendedApi')
diff --git a/lib/connect.js b/lib/connect.js
index 343ba2066f..9bfbe84834 100644
--- a/lib/connect.js
+++ b/lib/connect.js
@@ -1,12 +1,12 @@
 'use strict'
 
-const tls = require('tls')
-const Parser = require('redis-parser')
 const net = require('net')
-const onConnect = require('./readyHandler')
+const Parser = require('redis-parser')
+const tls = require('tls')
 const debug = require('./debug')
-const replyHandler = require('./replyHandler')
 const flushAndError = require('./flushAndError')
+const onConnect = require('./readyHandler')
+const replyHandler = require('./replyHandler')
 const onResult = replyHandler.onResult
 const onError = replyHandler.onError
 
diff --git a/lib/extendedApi.js b/lib/extendedApi.js
deleted file mode 100644
index 59cafce930..0000000000
--- a/lib/extendedApi.js
+++ /dev/null
@@ -1,116 +0,0 @@
-'use strict'
-
-const utils = require('./utils')
-const debug = require('./debug')
-const RedisClient = require('../').RedisClient
-const Command = require('./command')
-const Multi = require('./multi')
-const flushAndError = require('./flushAndError')
-const noop = function () {}
-
-/**********************************************
-All documented and exposed API belongs in here
-**********************************************/
-
-// Redirect calls to the appropriate function and use to send arbitrary / not supported commands
-// TODO: REMOVE sendCommand and replace it by a function to add new commands
-// TODO: Add a library to add the sendCommand back in place for legacy reasons
-RedisClient.prototype.sendCommand = function (command, args) {
-  // Throw to fail early instead of relying in order in this case
-  if (typeof command !== 'string') {
-    throw new TypeError(`Wrong input type "${command !== null && command !== undefined ? command.constructor.name : command}" for command name`)
-  }
-  if (!Array.isArray(args)) {
-    if (args === undefined || args === null) {
-      args = []
-    } else {
-      throw new TypeError(`Wrong input type "${args.constructor.name}" for args`)
-    }
-  }
-
-  // Using the raw multi command is only possible with this function
-  // If the command is not yet added to the client, the internal function should be called right away
-  // Otherwise we need to redirect the calls to make sure the internal functions don't get skipped
-  // The internal functions could actually be used for any non hooked function
-  // but this might change from time to time and at the moment there's no good way to distinguish them
-  // from each other, so let's just do it do it this way for the time being
-  if (command === 'multi' || typeof this[command] !== 'function') {
-    return this.internalSendCommand(new Command(command, args))
-  }
-  return this[command].apply(this, args)
-}
-
-RedisClient.prototype.end = function (flush) {
-  if (typeof flush !== 'boolean') {
-    throw new TypeError('You must call "end" with the flush argument.')
-  }
-
-  // Flush queue if wanted
-  if (flush) {
-    flushAndError(this, 'Connection forcefully ended and command aborted.', 'NR_CLOSED')
-  }
-  // Clear retryTimer
-  if (this.retryTimer) {
-    clearTimeout(this.retryTimer)
-    this.retryTimer = null
-  }
-  this._stream.removeAllListeners()
-  this._stream.on('error', noop)
-  this.connected = false
-  this.ready = false
-  this.closing = true
-  return this._stream.destroySoon()
-}
-
-RedisClient.prototype.unref = function () {
-  if (this.connected) {
-    debug('Unref\'ing the socket connection')
-    this._stream.unref()
-  } else {
-    debug('Not connected yet, will unref later')
-    this.once('connect', function () {
-      this.unref()
-    })
-  }
-}
-
-// TODO: promisify this
-RedisClient.prototype.duplicate = function (options, callback) {
-  if (typeof options === 'function') {
-    callback = options
-    options = null
-  }
-  const existingOptions = utils.clone(this.options)
-  options = utils.clone(options)
-  for (const elem in options) {
-    if (options.hasOwnProperty(elem)) {
-      existingOptions[elem] = options[elem]
-    }
-  }
-  const client = new RedisClient(existingOptions)
-  client.selectedDb = this.selectedDb
-  if (typeof callback === 'function') {
-    const errorListener = function (err) {
-      callback(err)
-      client.end(true)
-    }
-    const readyListener = function () {
-      callback(null, client)
-      client.removeAllListeners(errorListener)
-    }
-    client.once('ready', readyListener)
-    client.once('error', errorListener)
-    return client
-  }
-  return client
-}
-
-// Note: this overrides a native function!
-RedisClient.prototype.multi = function multi (args) {
-  return new Multi(this, 'multi', args)
-}
-
-// Note: This is not a native function but is still handled as a individual command as it behaves just the same as multi
-RedisClient.prototype.batch = function batch (args) {
-  return new Multi(this, 'batch', args)
-}
diff --git a/lib/individualCommands.js b/lib/individualCommands.js
index 23b559d318..7b9f8835ef 100644
--- a/lib/individualCommands.js
+++ b/lib/individualCommands.js
@@ -1,8 +1,8 @@
 'use strict'
 
+const Command = require('./command')
 const debug = require('./debug')
 const Multi = require('./multi')
-const Command = require('./command')
 const utils = require('./utils')
 const noPasswordIsSet = /no password is set/
 const RedisClient = require('../').RedisClient
diff --git a/lib/multi.js b/lib/multi.js
index 9291cb61b9..27aa21932d 100644
--- a/lib/multi.js
+++ b/lib/multi.js
@@ -1,9 +1,9 @@
 'use strict'
 
-const Errors = require('redis-errors')
 const Queue = require('denque')
-const utils = require('./utils')
+const Errors = require('redis-errors')
 const Command = require('./command')
+const utils = require('./utils')
 const handleReply = utils.handleReply
 
 /**
diff --git a/lib/offlineCommand.js b/lib/offlineCommand.js
index 8893d04097..55d44bdf33 100644
--- a/lib/offlineCommand.js
+++ b/lib/offlineCommand.js
@@ -1,8 +1,8 @@
 'use strict'
 
 const Errors = require('redis-errors')
-const utils = require('./utils')
 const debug = require('./debug')
+const utils = require('./utils')
 
 function offlineCommand (client, command) {
   const commandName = command.command.toUpperCase()
diff --git a/lib/readyHandler.js b/lib/readyHandler.js
index 415e054aed..e641e9bdd2 100644
--- a/lib/readyHandler.js
+++ b/lib/readyHandler.js
@@ -1,7 +1,7 @@
 'use strict'
 
-const debug = require('./debug')
 const Command = require('./command')
+const debug = require('./debug')
 const utils = require('./utils')
 
 function onConnect (client) {
diff --git a/lib/reconnect.js b/lib/reconnect.js
index 8fc407ac34..a9fc647bd2 100644
--- a/lib/reconnect.js
+++ b/lib/reconnect.js
@@ -1,9 +1,9 @@
 'use strict'
 
 const Errors = require('redis-errors')
+const connect = require('./connect')
 const debug = require('./debug')
 const flushAndError = require('./flushAndError')
-const connect = require('./connect')
 
 /**
  * @description Try connecting to a server again
diff --git a/lib/replyHandler.js b/lib/replyHandler.js
index 9fd5e77bb2..631f529743 100644
--- a/lib/replyHandler.js
+++ b/lib/replyHandler.js
@@ -1,8 +1,8 @@
 'use strict'
 
 const Buffer = require('buffer').Buffer
-const utils = require('./utils')
 const pubsub = require('./pubsub')
+const utils = require('./utils')
 
 function onError (client, err) {
   const commandObj = client.commandQueue.shift()
diff --git a/lib/utils.js b/lib/utils.js
index 1a146774ec..5fea2a008a 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -149,6 +149,11 @@ function handleReply (client, reply, command) {
   return reply
 }
 
+/**
+ * @description Set default reconnect variables
+ *
+ * @param {RedisClient} client
+ */
 function setReconnectDefaults (client) {
   client.retryTimer = null
   client.retryTotaltime = 0
diff --git a/lib/writeCommands.js b/lib/writeCommands.js
index 7bb0cc5cff..4c8ff8be75 100644
--- a/lib/writeCommands.js
+++ b/lib/writeCommands.js
@@ -1,8 +1,8 @@
 'use strict'
 
 const Commands = require('redis-commands')
-const utils = require('./utils')
 const debug = require('./debug')
+const utils = require('./utils')
 // const isUint8Array = (() => {
 //   try {
 //     return process.binding('util').isUint8Array
diff --git a/package.json b/package.json
index 976dbfdfb2..4559285004 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
     "test": "nyc --cache mocha ./test/*.js ./test/commands/*.js --timeout=8000",
     "posttest": "npm run coverage",
     "compare": "node benchmarks/diff_multi_bench_output.js beforeBench.txt afterBench.txt",
-    "lint": "eslint . --fix"
+    "lint": "standard . --fix"
   },
   "dependencies": {
     "denque": "^1.1.1",