diff --git a/index.js b/index.js
index 77329e4..6eadcaa 100644
--- a/index.js
+++ b/index.js
@@ -1,105 +1,105 @@
-var Transform = require('readable-stream').Transform;
-var inherits = require('inherits');
-var cyclist = require('cyclist');
-var util = require('util');
-
-var ParallelTransform = function(maxParallel, opts, ontransform) {
-	if (!(this instanceof ParallelTransform)) return new ParallelTransform(maxParallel, opts, ontransform);
+const {Transform} = require('stream');
+const cyclist = require('cyclist');
+
+class ParallelTransform extends Transform {
+	constructor(maxParallel, opts, ontransform) {
+		if (typeof maxParallel === 'function') {
+			ontransform = maxParallel;
+			opts = null;
+			maxParallel = 1;
+		}
+		if (typeof opts === 'function') {
+			ontransform = opts;
+			opts = null;
+		}
 
-	if (typeof maxParallel === 'function') {
-		ontransform = maxParallel;
-		opts = null;
-		maxParallel = 1;
+		if (!opts) opts = {};
+		if (!opts.highWaterMark) opts.highWaterMark = Math.max(maxParallel, 16);
+		if (opts.objectMode !== false) opts.objectMode = true;
+
+		super(opts);
+
+		this._maxParallel = maxParallel;
+		this._ontransform = ontransform;
+		this._destroyed = false;
+		this._flushed = false;
+		this._ordered = opts.ordered !== false;
+		this._buffer = this._ordered ? cyclist(maxParallel) : [];
+		this._top = 0;
+		this._bottom = 0;
+		this._ondrain = null;
 	}
-	if (typeof opts === 'function') {
-		ontransform = opts;
-		opts = null;
-	}
-
-	if (!opts) opts = {};
-	if (!opts.highWaterMark) opts.highWaterMark = Math.max(maxParallel, 16);
-	if (opts.objectMode !== false) opts.objectMode = true;
-
-	Transform.call(this, opts);
 
-	this._maxParallel = maxParallel;
-	this._ontransform = ontransform;
-	this._destroyed = false;
-	this._flushed = false;
-	this._ordered = opts.ordered !== false;
-	this._buffer = this._ordered ? cyclist(maxParallel) : [];
-	this._top = 0;
-	this._bottom = 0;
-	this._ondrain = null;
-};
-
-inherits(ParallelTransform, Transform);
+	destroy() {
+		if (this._destroyed) return;
+		this._destroyed = true;
+		this.emit('close');
+	}
 
-ParallelTransform.prototype.destroy = function() {
-	if (this._destroyed) return;
-	this._destroyed = true;
-	this.emit('close');
-};
+	_transform (chunk, enc, callback) {
+		const self = this;
+		const pos = this._top++;
+
+		this._ontransform(chunk, function(err, data) {
+			if (self._destroyed) return;
+			if (err) {
+				self.emit('error', err);
+				self.push(null);
+				self.destroy();
+				return;
+			}
+			if (self._ordered) {
+				self._buffer.put(pos, (data === undefined || data === null) ? null : data);
+			}
+			else {
+				self._buffer.push(data);
+			}
+			self._drain();
+		});
+
+		if (this._top - this._bottom < this._maxParallel) return callback();
+		this._ondrain = callback;
+	}
 
-ParallelTransform.prototype._transform = function(chunk, enc, callback) {
-	var self = this;
-	var pos = this._top++;
+	_flush (callback) {
+		this._flushed = true;
+		this._ondrain = callback;
+		this._drain();
+	}
 
-	this._ontransform(chunk, function(err, data) {
-		if (self._destroyed) return;
-		if (err) {
-			self.emit('error', err);
-			self.push(null);
-			self.destroy();
-			return;
-		}
-		if (self._ordered) {
-			self._buffer.put(pos, (data === undefined || data === null) ? null : data);
+	_drain () {
+		let data;
+		if (this._ordered) {
+			while (this._buffer.get(this._bottom) !== undefined) {
+				data = this._buffer.del(this._bottom++);
+				if (data === null) continue;
+				this.push(data);
+			}
 		}
 		else {
-			self._buffer.push(data);
+			while (this._buffer.length > 0) {
+				data = this._buffer.pop();
+				this._bottom++;
+				if (data === null) continue;
+				this.push(data);
+			}
 		}
-		self._drain();
-	});
-
-	if (this._top - this._bottom < this._maxParallel) return callback();
-	this._ondrain = callback;
-};
 
-ParallelTransform.prototype._flush = function(callback) {
-	this._flushed = true;
-	this._ondrain = callback;
-	this._drain();
-};
+		if (!this._drained() || !this._ondrain) return;
 
-ParallelTransform.prototype._drain = function() {
-	if (this._ordered) {
-		while (this._buffer.get(this._bottom) !== undefined) {
-			var data = this._buffer.del(this._bottom++);
-			if (data === null) continue;
-			this.push(data);
-		}
+		const ondrain = this._ondrain;
+		this._ondrain = null;
+		ondrain();
 	}
-	else {
-		while (this._buffer.length > 0) {
-			var data =  this._buffer.pop();
-			this._bottom++;
-			if (data === null) continue;
-			this.push(data);
-		}
-	}
-
 
-	if (!this._drained() || !this._ondrain) return;
-
-	var ondrain = this._ondrain;
-	this._ondrain = null;
-	ondrain();
-};
+	_drained () {
+		let diff = this._top - this._bottom;
+		return this._flushed ? !diff : diff < this._maxParallel;
+	};
+}
 
-ParallelTransform.prototype._drained = function() {
-	var diff = this._top - this._bottom;
-	return this._flushed ? !diff : diff < this._maxParallel;
+module.exports = function parallelTransform(maxParallel, opts, ontransform) {
+	return new ParallelTransform(maxParallel, opts, ontransform);
 };
 
-module.exports = ParallelTransform;
+module.exports.ParallelTransform = ParallelTransform;
diff --git a/package.json b/package.json
index 5c3c570..605ad44 100644
--- a/package.json
+++ b/package.json
@@ -13,8 +13,6 @@
   ],
   "author": "Mathias Buus Madsen <mathiasbuus@gmail.com>",
   "dependencies": {
-    "cyclist": "~0.2.2",
-    "inherits": "^2.0.3",
-    "readable-stream": "^2.1.5"
+    "cyclist": "~0.2.2"
   }
 }