diff --git a/README.md b/README.md
index 3c006e5..7af772e 100644
--- a/README.md
+++ b/README.md
@@ -41,45 +41,30 @@ npm install aedes-cached-persistence --save
 In order to reuse aedes-cached-persistence, you need to:
 
 ```js
-'use strict'
-
-var util = require('util')
-var CachedPersistence = require('aedes-cached-persistence')
+const CachedPersistence = require('aedes-cached-persistence')
 
 // if you need http://npm.im/aedes-packet, it is available
 // from this module as well
-// var Packet = CachedPersistence.Packet
-
-function MyPersistence (opts) {
-  if (!(this instanceof MyPersistence)) {
-    return new MyPersistence(opts)
-  }
-  // initialize your data here
-
-  CachedPersistence.call(this, opts)
-}
-
-util.inherits(MyPersistence, CachedPersistence)
-
-MyPersistence.prototype.addSubscriptions = function (client, subs, cb) {
-  // ..persistence specific implementation..
-
-  // call this._addedSubscriptions when you are done
-  this._addedSubscriptions(client, subsObjs, cb)
-}
-
-MyPersistence.prototype.removeSubscriptions = function (client, subs, cb) {
-  // ..persistence specific implementation..
-
-  // call this._addedSubscriptions when you are done
-  this._removedSubscriptions(client, subs.map(subs, client), cb)
+// const { Packet } = CachedPersistence
+
+class MyPersistence extends CachedPersistence {
+    constructor(opts) {
+       super(opts)
+    }
+    addSubscriptions(client, subs, cb) {
+        // ..persistence specific implementation..
+        // call super._addedSubscriptions when you are done
+        super._addedSubscriptions(client, subs.map(mapSub), cb)
+    }
+    removeSubscriptions(client, subs, cb) {
+        // ..persistence specific implementation..
+        // call super._removedSubscriptions when you are done
+        super._removedSubscriptions(client, subs.map(mapSub), cb)
+    }
 }
 
-function toSubObj (sub) {
-  return {
-    clientId: this.id,
-    topic: sub.topic
-  }
+function mapSub (sub) {
+  return { topic: sub.topic }
 }
 ```
 
diff --git a/index.js b/index.js
index 0b1f3fb..5c9fc40 100644
--- a/index.js
+++ b/index.js
@@ -1,12 +1,8 @@
-/* eslint-disable no-var */
-'use strict'
-
 const QlobberSub = require('qlobber/aedes/qlobber-sub')
 const { Packet } = require('aedes-persistence')
-const EE = require('events').EventEmitter
-const inherits = require('util').inherits
 const MultiStream = require('multistream')
 const parallel = require('fastparallel')
+const { EventEmitter } = require('events')
 const QlobberOpts = {
   wildcard_one: '+',
   wildcard_some: '#',
@@ -17,208 +13,203 @@ const newSubTopic = '$SYS/sub/add'
 const rmSubTopic = '$SYS/sub/rm'
 const subTopic = '$SYS/sub/+'
 
-function CachedPersistence (opts) {
-  if (!(this instanceof CachedPersistence)) {
-    return new CachedPersistence(opts)
-  }
-
-  EE.call(this)
+class CachedPersistence extends EventEmitter {
+  constructor (opts) {
+    super()
 
-  this.ready = false
-  this.destroyed = false
-  this._parallel = parallel()
-  this._trie = new QlobberSub(QlobberOpts)
-  this._waiting = {}
+    this.ready = false
+    this.destroyed = false
+    this._parallel = parallel()
+    this._trie = new QlobberSub(QlobberOpts)
+    this._waiting = new Map()
 
-  const that = this
+    this.once('ready', () => {
+      this.ready = true
+    })
 
-  this.once('ready', function () {
-    that.ready = true
-  })
+    this._onSubMessage = this._onMessage.bind(this)
+  }
 
-  this._onMessage = function onSubMessage (packet, cb) {
+  _onMessage (packet, cb) {
     const decoded = JSON.parse(packet.payload)
     const clientId = decoded.clientId
-    for (var i = 0; i < decoded.subs.length; i++) {
+    for (let i = 0; i < decoded.subs.length; i++) {
       const sub = decoded.subs[i]
       sub.clientId = clientId
       if (packet.topic === newSubTopic) {
         if (sub.qos > 0) {
-          that._trie.add(sub.topic, sub)
+          this._trie.add(sub.topic, sub)
         } else {
-          that._trie.remove(sub.topic, sub)
+          this._trie.remove(sub.topic, sub)
         }
       } else if (packet.topic === rmSubTopic) {
-        that._trie.remove(sub.topic, sub)
+        this._trie.remove(sub.topic, sub)
       }
     }
-    const action = packet.topic === newSubTopic ? 'sub_' : 'unsub_'
-    var key = clientId + '-' + action
+
     if (decoded.subs.length > 0) {
-      key = clientId + '-' + action + decoded.subs[0].topic
-    }
-    const waiting = that._waiting[key]
-    that._waiting[key] = undefined
-    if (waiting) {
-      process.nextTick(waiting)
+      const key = getKey(clientId, packet.topic === newSubTopic, decoded.subs[0].topic)
+      const waiting = this._waiting.get(key)
+      if (waiting) {
+        this._waiting.delete(key)
+        process.nextTick(waiting)
+      }
     }
     cb()
   }
-}
 
-inherits(CachedPersistence, EE)
-
-CachedPersistence.prototype._waitFor = function (client, action, cb) {
-  this._waiting[client.id + '-' + action] = cb
-}
+  get broker () {
+    return this._broker
+  }
 
-CachedPersistence.prototype._addedSubscriptions = function (client, subs, cb) {
-  if (!this.ready) {
-    this.once('ready', this._addedSubscriptions.bind(this, client, subs, cb))
-    return
+  set broker (broker) {
+    this._broker = broker
+    this.broker.subscribe(subTopic, this._onSubMessage, this._setup.bind(this))
   }
 
-  var errored = false
+  _waitFor (client, isSub, topic, cb) {
+    this._waiting.set(getKey(client.id, isSub, topic), cb)
+  }
 
-  this._waitFor(client, 'sub_' + subs[0].topic, function (err) {
-    if (!errored && err) {
-      return cb(err)
+  _addedSubscriptions (client, subs, cb) {
+    if (!this.ready) {
+      this.once('ready', this._addedSubscriptions.bind(this, client, subs, cb))
+      return
     }
-    if (!errored) {
-      cb(null, client)
+
+    if (subs.length === 0) {
+      return cb(null, client)
     }
-  })
 
-  if (subs.length === 0) {
-    return cb(null, client)
-  }
+    let errored = false
 
-  const ctx = {
-    cb: cb || noop,
-    client: client,
-    broker: this._broker,
-    topic: newSubTopic,
-    brokerPublish: brokerPublish
+    this._waitFor(client, true, subs[0].topic, (err) => {
+      if (!errored && err) {
+        return cb(err)
+      }
+      if (!errored) {
+        cb(null, client)
+      }
+    })
+
+    const ctx = {
+      cb: cb || noop,
+      client,
+      broker: this._broker,
+      topic: newSubTopic,
+      brokerPublish
+    }
+    ctx.brokerPublish(subs, (err) => {
+      if (err) {
+        errored = true
+        cb(err)
+      }
+    })
   }
-  ctx.brokerPublish(subs, function (err) {
-    if (err) {
-      errored = true
-      cb(err)
+
+  _removedSubscriptions (client, subs, cb) {
+    if (!this.ready) {
+      this.once('ready', this._removedSubscriptions.bind(this, client, subs, cb))
+      return
     }
-  })
-}
+    let errored = false
+    let key = subs
 
-function brokerPublish (subs, cb) {
-  const encoded = JSON.stringify({ clientId: this.client.id, subs: subs })
-  const packet = new Packet({
-    topic: this.topic,
-    payload: encoded
-  })
-  this.broker.publish(packet, cb)
-}
+    if (subs.length > 0) {
+      key = subs[0].topic
+    }
+    this._waitFor(client, false, key, (err) => {
+      if (!errored && err) {
+        return cb(err)
+      }
+      if (!errored) {
+        cb(null, client)
+      }
+    })
+
+    const ctx = {
+      cb: cb || noop,
+      client,
+      broker: this._broker,
+      topic: rmSubTopic,
+      brokerPublish
+    }
+    ctx.brokerPublish(subs, (err) => {
+      if (err) {
+        errored = true
+        cb(err)
+      }
+    })
+  }
 
-function noop () {}
+  subscriptionsByTopic (topic, cb) {
+    if (!this.ready) {
+      this.once('ready', this.subscriptionsByTopic.bind(this, topic, cb))
+      return this
+    }
 
-CachedPersistence.prototype._removedSubscriptions = function (client, subs, cb) {
-  if (!this.ready) {
-    this.once('ready', this._removedSubscriptions.bind(this, client, subs, cb))
-    return
+    cb(null, this._trie.match(topic))
   }
-  var errored = false
-  var key = subs
 
-  if (subs.length > 0) {
-    key = subs[0].topic
+  cleanSubscriptions (client, cb) {
+    this.subscriptionsByClient(client, (err, subs, client) => {
+      if (err || !subs) { return cb(err, client) }
+      subs = subs.map(subToTopic)
+      this.removeSubscriptions(client, subs, cb)
+    })
   }
-  this._waitFor(client, 'unsub_' + key, function (err) {
-    if (!errored && err) {
-      return cb(err)
-    }
-    if (!errored) {
-      cb(null, client)
-    }
-  })
 
-  const ctx = {
-    cb: cb || noop,
-    client: client,
-    broker: this._broker,
-    topic: rmSubTopic,
-    brokerPublish: brokerPublish
+  outgoingEnqueueCombi (subs, packet, cb) {
+    this._parallel({
+      persistence: this,
+      packet
+    }, outgoingEnqueue, subs, cb)
+  }
+
+  createRetainedStreamCombi (patterns) {
+    const streams = patterns.map((p) => {
+      return this.createRetainedStream(p)
+    })
+    return MultiStream.obj(streams)
   }
-  ctx.brokerPublish(subs, function (err) {
-    if (err) {
-      errored = true
-      cb(err)
-    }
-  })
-}
 
-CachedPersistence.prototype.subscriptionsByTopic = function (topic, cb) {
-  if (!this.ready) {
-    this.once('ready', this.subscriptionsByTopic.bind(this, topic, cb))
-    return this
+  destroy (cb) {
+    this.destroyed = true
+    this.broker.unsubscribe(subTopic, this._onSubMessage, () => {
+      if (cb) {
+        cb()
+      }
+    })
   }
 
-  cb(null, this._trie.match(topic))
+  // must emit 'ready'
+  _setup () {
+    this.emit('ready')
+  }
 }
 
-CachedPersistence.prototype.cleanSubscriptions = function (client, cb) {
-  const that = this
-  this.subscriptionsByClient(client, function (err, subs, client) {
-    if (err || !subs) { return cb(err, client) }
-    subs = subs.map(subToTopic)
-    that.removeSubscriptions(client, subs, cb)
+function brokerPublish (subs, cb) {
+  const encoded = JSON.stringify({ clientId: this.client.id, subs })
+  const packet = new Packet({
+    topic: this.topic,
+    payload: encoded
   })
+  this.broker.publish(packet, cb)
 }
 
-CachedPersistence.prototype.outgoingEnqueueCombi = function (subs, packet, cb) {
-  this._parallel({
-    persistence: this,
-    packet: packet
-  }, outgoingEnqueue, subs, cb)
-}
+function noop () { }
 
 function outgoingEnqueue (sub, cb) {
   this.persistence.outgoingEnqueue(sub, this.packet, cb)
 }
 
-CachedPersistence.prototype.createRetainedStreamCombi = function (patterns) {
-  const that = this
-  const streams = patterns.map(function (p) {
-    return that.createRetainedStream(p)
-  })
-  return MultiStream.obj(streams)
-}
-
-CachedPersistence.prototype.destroy = function (cb) {
-  this.destroyed = true
-  this.broker.unsubscribe(subTopic, this._onMessage, function () {
-    if (cb) {
-      cb()
-    }
-  })
-}
-
-// must emit 'ready'
-CachedPersistence.prototype._setup = function () {
-  this.emit('ready')
-}
-
 function subToTopic (sub) {
   return sub.topic
 }
 
-Object.defineProperty(CachedPersistence.prototype, 'broker', {
-  enumerable: false,
-  get: function () {
-    return this._broker
-  },
-  set: function (broker) {
-    this._broker = broker
-    this.broker.subscribe(subTopic, this._onMessage, this._setup.bind(this))
-  }
-})
+function getKey (clientId, isSub, topic) {
+  return clientId + '-' + (isSub ? 'sub_' : 'unsub_') + (topic || '')
+}
 
 module.exports = CachedPersistence
 module.exports.Packet = Packet
diff --git a/package.json b/package.json
index 6c41def..3df6de9 100644
--- a/package.json
+++ b/package.json
@@ -35,7 +35,7 @@
     "test"
   ],
   "engines": {
-    "node": ">=10"
+    "node": ">=14"
   },
   "repository": {
     "type": "git",
@@ -54,24 +54,24 @@
   },
   "homepage": "https://github.com/moscajs/aedes-cached-persistence#readme",
   "devDependencies": {
-    "aedes": "^0.45.0",
+    "aedes": "^0.46.3",
     "concat-stream": "^2.0.0",
     "faucet": "0.0.1",
     "license-checker": "^25.0.1",
-    "mqemitter": "^4.4.1",
+    "mqemitter": "^4.5.0",
     "nyc": "^15.1.0",
     "pump": "^3.0.0",
-    "release-it": "^14.2.2",
+    "release-it": "^15.0.0",
     "snazzy": "^9.0.0",
-    "standard": "^16.0.3",
+    "standard": "^17.0.0",
     "tape": "^5.2.1",
     "through2": "^4.0.2",
-    "tsd": "^0.14.0"
+    "tsd": "^0.20.0"
   },
   "dependencies": {
     "aedes-persistence": "^9.1.2",
-    "fastparallel": "^2.4.0",
-    "multistream": "^4.0.1",
+    "fastparallel": "^2.4.1",
+    "multistream": "^4.1.0",
     "qlobber": "^7.0.0"
   }
 }
diff --git a/test.js b/test.js
index 13a2e06..58da531 100644
--- a/test.js
+++ b/test.js
@@ -31,7 +31,7 @@ class MyPersistence extends CachedPersistence {
       if (err) {
         return cb(err)
       }
-      this._addedSubscriptions(client, subs, cb)
+      super._addedSubscriptions(client, subs, cb)
     })
   }
 
@@ -43,7 +43,7 @@ class MyPersistence extends CachedPersistence {
       const subsObjs = topics.map(function mapSub (topic) {
         return { topic }
       })
-      this._removedSubscriptions(client, subsObjs, cb)
+      super._removedSubscriptions(client, subsObjs, cb)
     })
   }
 }