diff --git a/lib/AsyncDependenciesBlock.js b/lib/AsyncDependenciesBlock.js
index 08f583c62..438a481ae 100644
--- a/lib/AsyncDependenciesBlock.js
+++ b/lib/AsyncDependenciesBlock.js
@@ -2,61 +2,55 @@
 	MIT License http://www.opensource.org/licenses/mit-license.php
 	Author Tobias Koppers @sokra
 */
-var DependenciesBlock = require("./DependenciesBlock");
+"use strict";
+const DependenciesBlock = require("./DependenciesBlock");
 
-function AsyncDependenciesBlock(name, module, loc) {
-	DependenciesBlock.call(this);
-	this.chunkName = name;
-	this.chunks = null;
-	this.module = module;
-	this.loc = loc;
+module.exports = class AsyncDependenciesBlock extends DependenciesBlock {
+	constructor(name, module, loc) {
+		super();
+		this.chunkName = name;
+		this.chunks = null;
+		this.module = module;
+		this.loc = loc;
 
-	Object.defineProperty(this, "chunk", {
-		get: function() {
-			throw new Error("`chunk` was been renamed to `chunks` and is now an array");
-		},
-		set: function() {
-			throw new Error("`chunk` was been renamed to `chunks` and is now an array");
-		}
-	});
-
-}
-module.exports = AsyncDependenciesBlock;
-
-AsyncDependenciesBlock.prototype = Object.create(DependenciesBlock.prototype);
-AsyncDependenciesBlock.prototype.constructor = AsyncDependenciesBlock;
-
-AsyncDependenciesBlock.prototype.updateHash = function updateHash(hash) {
-	hash.update(this.chunkName || "");
-	hash.update(this.chunks && this.chunks.map(function(chunk) {
-		return typeof chunk.id === "number" ? chunk.id : "";
-	}).join(",") || "");
-	DependenciesBlock.prototype.updateHash.call(this, hash);
-};
-
-AsyncDependenciesBlock.prototype.disconnect = function() {
-	this.chunks = null;
-	DependenciesBlock.prototype.disconnect.call(this);
-};
-
-AsyncDependenciesBlock.prototype.unseal = function() {
-	this.chunks = null;
-	DependenciesBlock.prototype.unseal.call(this);
-};
-
-AsyncDependenciesBlock.prototype.sortItems = function() {
-	DependenciesBlock.prototype.sortItems.call(this);
-	if(this.chunks) {
-		this.chunks.sort(function(a, b) {
-			var i = 0;
-			while(true) { // eslint-disable-line no-constant-condition
-				if(!a.modules[i] && !b.modules[i]) return 0;
-				if(!a.modules[i]) return -1;
-				if(!b.modules[i]) return 1;
-				if(a.modules[i].id > b.modules[i].id) return 1;
-				if(a.modules[i].id < b.modules[i].id) return -1;
-				i++;
+		Object.defineProperty(this, "chunk", {
+			get: function() {
+				throw new Error("`chunk` was been renamed to `chunks` and is now an array");
+			},
+			set: function() {
+				throw new Error("`chunk` was been renamed to `chunks` and is now an array");
 			}
 		});
 	}
-};
+	updateHash(hash) {
+		hash.update(this.chunkName || "");
+		hash.update(this.chunks && this.chunks.map((chunk) => {
+			return typeof chunk.id === "number" ? chunk.id : "";
+		}).join(",").replace(/,\s*$/, "") || "");
+		super.updateHash(hash);
+	}
+	disconnect() {
+		this.chunks = null;
+		super.disconnect();
+	}
+	unseal() {
+		this.chunks = null;
+		super.unseal();
+	}
+	sortItems() {
+		super.sortItems();
+		if(this.chunks) {
+			this.chunks.sort((a, b) => {
+				let i = 0;
+				while(true) { // eslint-disable-line no-constant-condition
+					if(!a.modules[i] && !b.modules[i]) return 0;
+					if(!a.modules[i]) return -1;
+					if(!b.modules[i]) return 1;
+					if(a.modules[i].id > b.modules[i].id) return 1;
+					if(a.modules[i].id < b.modules[i].id) return -1;
+					i++;
+				}
+			});
+		}
+	}
+}