diff --git a/examples/aggressive-merging/webpack.config.js b/examples/aggressive-merging/webpack.config.js
index 9b651f2f7..739102bb7 100644
--- a/examples/aggressive-merging/webpack.config.js
+++ b/examples/aggressive-merging/webpack.config.js
@@ -1,6 +1,7 @@
 var path = require("path");
 var AggressiveMergingPlugin = require("../../lib/optimize/AggressiveMergingPlugin");
 module.exports = {
+	mode: "production",
 	entry: {
 		pageA: "./pageA",
 		pageB: "./pageB",
diff --git a/examples/build-common.js b/examples/build-common.js
index 24b61463f..a7be20941 100644
--- a/examples/build-common.js
+++ b/examples/build-common.js
@@ -11,9 +11,11 @@ const fs = require("fs");
 
 const extraArgs = "";
 
-const targetArgs = global.NO_TARGET_ARGS ? "" : " ./example.js js/output.js";
+const hasConfiguration = fs.existsSync("webpack.config.js");
+const targetArgs = global.NO_TARGET_ARGS ? "" : " ./example.js js/output.js ";
 const displayReasons = global.NO_REASONS ? "" : " --display-reasons --display-used-exports --display-provided-exports";
-cp.exec(`node ${path.resolve(__dirname, "../bin/webpack.js")} ${displayReasons} --display-chunks --display-max-modules 99999 --display-origins --display-entrypoints --output-public-path "js/" -p ${extraArgs} ${targetArgs}`, function(error, stdout, stderr) {
+const modeArgs = hasConfiguration ? "" : "--mode production";
+cp.exec(`node ${path.resolve(__dirname, "../bin/webpack.js")} ${modeArgs} ${displayReasons} --display-chunks --display-max-modules 99999 --display-origins --display-entrypoints --output-public-path "js/" -p ${extraArgs} ${targetArgs}`, function(error, stdout, stderr) {
 	if(stderr)
 		console.log(stderr);
 	if(error !== null)
@@ -25,7 +27,7 @@ cp.exec(`node ${path.resolve(__dirname, "../bin/webpack.js")} ${displayReasons}
 		console.log(stderr);
 		throw e;
 	}
-	cp.exec(`node ${path.resolve(__dirname, "../bin/webpack.js")} ${displayReasons} --display-chunks --display-max-modules 99999 --display-origins --display-entrypoints --output-public-path "js/" --output-pathinfo ${extraArgs} ${targetArgs}`, function(error, stdout, stderr) {
+	cp.exec(`node ${path.resolve(__dirname, "../bin/webpack.js")} ${modeArgs} ${displayReasons} --display-chunks --display-max-modules 99999 --display-origins --display-entrypoints --output-public-path "js/" --output-pathinfo ${extraArgs} ${targetArgs}`, function(error, stdout, stderr) {
 		console.log(stdout);
 		if(stderr)
 			console.log(stderr);
diff --git a/examples/chunkhash/webpack.config.js b/examples/chunkhash/webpack.config.js
index 817f492b3..27afca015 100644
--- a/examples/chunkhash/webpack.config.js
+++ b/examples/chunkhash/webpack.config.js
@@ -1,6 +1,7 @@
 var path = require("path");
 var webpack = require("../../");
 module.exports = {
+	mode: "production",
 	entry: {
 		main: "./example",
 		common: ["./vendor"] // optional
diff --git a/examples/code-splitted-css-bundle/webpack.config.js b/examples/code-splitted-css-bundle/webpack.config.js
index d443e0a2f..c182c3d51 100644
--- a/examples/code-splitted-css-bundle/webpack.config.js
+++ b/examples/code-splitted-css-bundle/webpack.config.js
@@ -1,6 +1,7 @@
 const LoaderOptionsPlugin = require("../../lib/LoaderOptionsPlugin");
 const ExtractTextPlugin = require("extract-text-webpack-plugin");
 module.exports = {
+	mode: "production",
 	module: {
 		rules: [
 			{
diff --git a/examples/coffee-script/webpack.config.js b/examples/coffee-script/webpack.config.js
index 8bd41bcf4..bdb91adf8 100644
--- a/examples/coffee-script/webpack.config.js
+++ b/examples/coffee-script/webpack.config.js
@@ -1,4 +1,5 @@
 module.exports = {
+	mode: "production",
 	module: {
 		rules: [
 			{ test: /\.coffee$/, loader: "coffee-loader" }
diff --git a/examples/common-chunk-and-vendor-chunk/webpack.config.js b/examples/common-chunk-and-vendor-chunk/webpack.config.js
index a85c3e4eb..42f93af81 100644
--- a/examples/common-chunk-and-vendor-chunk/webpack.config.js
+++ b/examples/common-chunk-and-vendor-chunk/webpack.config.js
@@ -2,6 +2,7 @@ var path = require("path");
 var CommonsChunkPlugin = require("../../lib/optimize/CommonsChunkPlugin");
 
 module.exports = {
+	mode: "production",
 	entry: {
 		vendor: ["./vendor1", "./vendor2"],
 		pageA: "./pageA",
diff --git a/examples/common-chunk-grandchildren/webpack.config.js b/examples/common-chunk-grandchildren/webpack.config.js
index 7b2696d7b..047035e32 100644
--- a/examples/common-chunk-grandchildren/webpack.config.js
+++ b/examples/common-chunk-grandchildren/webpack.config.js
@@ -4,6 +4,7 @@ const path = require("path");
 
 module.exports = [
 	{
+		mode: "production",
 		entry: {
 			main: ["./example.js"]
 		},
@@ -21,6 +22,7 @@ module.exports = [
 		]
 	},
 	{
+		mode: "production",
 		entry: {
 			main: ["./example.js"]
 		},
diff --git a/examples/css-bundle/webpack.config.js b/examples/css-bundle/webpack.config.js
index ed5279ebd..530248cd0 100644
--- a/examples/css-bundle/webpack.config.js
+++ b/examples/css-bundle/webpack.config.js
@@ -1,6 +1,7 @@
 const LoaderOptionsPlugin = require("../../lib/LoaderOptionsPlugin");
 const ExtractTextPlugin = require("extract-text-webpack-plugin");
 module.exports = {
+	mode: "production",
 	module: {
 		rules: [
 			{
diff --git a/examples/dll-app-and-vendor/0-vendor/webpack.config.js b/examples/dll-app-and-vendor/0-vendor/webpack.config.js
index 89b48fa5e..8477db863 100644
--- a/examples/dll-app-and-vendor/0-vendor/webpack.config.js
+++ b/examples/dll-app-and-vendor/0-vendor/webpack.config.js
@@ -2,6 +2,7 @@ var path = require("path");
 var webpack = require("../../../");
 
 module.exports = {
+	mode: "production",
 	context: __dirname,
 	entry: ["example-vendor"],
 	output: {
diff --git a/examples/dll-app-and-vendor/1-app/webpack.config.js b/examples/dll-app-and-vendor/1-app/webpack.config.js
index 2a02109d0..02ff7b1f3 100644
--- a/examples/dll-app-and-vendor/1-app/webpack.config.js
+++ b/examples/dll-app-and-vendor/1-app/webpack.config.js
@@ -2,6 +2,7 @@ var path = require("path");
 var webpack = require("../../../");
 
 module.exports = {
+	mode: "production",
 	context: __dirname,
 	entry: "./example-app",
 	output: {
diff --git a/examples/dll-user/webpack.config.js b/examples/dll-user/webpack.config.js
index 45aed8fd9..a7ecc9527 100644
--- a/examples/dll-user/webpack.config.js
+++ b/examples/dll-user/webpack.config.js
@@ -1,6 +1,7 @@
 var path = require("path");
 var webpack = require("../../");
 module.exports = {
+	mode: "production",
 	plugins: [
 		new webpack.DllReferencePlugin({
 			context: path.join(__dirname, "..", "dll"),
diff --git a/examples/dll/webpack.config.js b/examples/dll/webpack.config.js
index e907576bd..12bfab15a 100644
--- a/examples/dll/webpack.config.js
+++ b/examples/dll/webpack.config.js
@@ -1,6 +1,7 @@
 var path = require("path");
 var webpack = require("../../");
 module.exports = {
+	mode: "production",
 	resolve: {
 		extensions: [".js", ".jsx"]
 	},
diff --git a/examples/explicit-vendor-chunk/webpack.config.js b/examples/explicit-vendor-chunk/webpack.config.js
index cf61f7439..43d54b4b9 100644
--- a/examples/explicit-vendor-chunk/webpack.config.js
+++ b/examples/explicit-vendor-chunk/webpack.config.js
@@ -3,6 +3,7 @@ var webpack = require("../../");
 module.exports = [
 	{
 		name: "vendor",
+		mode: "production",
 		entry: ["./vendor", "./vendor2"],
 		output: {
 			path: path.resolve(__dirname, "js"),
@@ -18,6 +19,7 @@ module.exports = [
 	},
 	{
 		name: "app",
+		mode: "production",
 		dependencies: ["vendor"],
 		entry: {
 			pageA: "./pageA",
diff --git a/examples/externals/webpack.config.js b/examples/externals/webpack.config.js
index fa5cddbc4..b3c40b98b 100644
--- a/examples/externals/webpack.config.js
+++ b/examples/externals/webpack.config.js
@@ -1,4 +1,5 @@
 module.exports = {
+	mode: "production",
 	output: {
 		libraryTarget: "umd"
 	},
diff --git a/examples/extra-async-chunk-advanced/webpack.config.js b/examples/extra-async-chunk-advanced/webpack.config.js
index 33a80ed0d..0e03a70f9 100644
--- a/examples/extra-async-chunk-advanced/webpack.config.js
+++ b/examples/extra-async-chunk-advanced/webpack.config.js
@@ -1,6 +1,7 @@
 var CommonsChunkPlugin = require("../../lib/optimize/CommonsChunkPlugin");
 
 module.exports = {
+	mode: "production",
 	plugins: [
 		new CommonsChunkPlugin({
 			name: "main",
diff --git a/examples/extra-async-chunk/webpack.config.js b/examples/extra-async-chunk/webpack.config.js
index f0331d1c0..413b70aa2 100644
--- a/examples/extra-async-chunk/webpack.config.js
+++ b/examples/extra-async-chunk/webpack.config.js
@@ -1,6 +1,7 @@
 var CommonsChunkPlugin = require("../../lib/optimize/CommonsChunkPlugin");
 
 module.exports = {
+	mode: "production",
 	plugins: [
 		new CommonsChunkPlugin({
 			// process all children of the main chunk
diff --git a/examples/harmony-library/webpack.config.js b/examples/harmony-library/webpack.config.js
index 50ef8f0b7..699800918 100644
--- a/examples/harmony-library/webpack.config.js
+++ b/examples/harmony-library/webpack.config.js
@@ -1,5 +1,6 @@
 var path = require("path");
 module.exports = {
+	mode: "production",
 	entry: "./example",
 	output: {
 		path: path.join(__dirname, "js"),
diff --git a/examples/harmony-unused/webpack.config.js b/examples/harmony-unused/webpack.config.js
new file mode 100644
index 000000000..4a357a8d0
--- /dev/null
+++ b/examples/harmony-unused/webpack.config.js
@@ -0,0 +1,6 @@
+module.exports = {
+	mode: "production",
+	optimization: {
+		concatenateModules: false
+	}
+};
diff --git a/examples/http2-aggressive-splitting/webpack.config.js b/examples/http2-aggressive-splitting/webpack.config.js
index e875b026f..cd0476ffd 100644
--- a/examples/http2-aggressive-splitting/webpack.config.js
+++ b/examples/http2-aggressive-splitting/webpack.config.js
@@ -1,6 +1,8 @@
 var path = require("path");
 var webpack = require("../../");
 module.exports = {
+	mode: "production",
+	cache: true, // better performance for the AggressiveSplittingPlugin
 	entry: "./example",
 	output: {
 		path: path.join(__dirname, "js"),
diff --git a/examples/hybrid-routing/webpack.config.js b/examples/hybrid-routing/webpack.config.js
index e9a3b08ce..1fe4e1d6d 100644
--- a/examples/hybrid-routing/webpack.config.js
+++ b/examples/hybrid-routing/webpack.config.js
@@ -1,6 +1,7 @@
 var path = require("path");
 var CommonsChunkPlugin = require("../../lib/optimize/CommonsChunkPlugin");
 module.exports = {
+	mode: "production",
 	entry: {
 		// The entry points for the pages
 		pageA: "./aEntry",
diff --git a/examples/i18n/webpack.config.js b/examples/i18n/webpack.config.js
index 30d446215..321c77f7d 100644
--- a/examples/i18n/webpack.config.js
+++ b/examples/i18n/webpack.config.js
@@ -7,6 +7,7 @@ var languages = {
 module.exports = Object.keys(languages).map(function(language) {
 	return {
 		name: language,
+		mode: "production",
 		entry: "./example",
 		output: {
 			path: path.join(__dirname, "js"),
diff --git a/examples/loader/webpack.config.js b/examples/loader/webpack.config.js
index 854df7f70..54fd5a1d5 100644
--- a/examples/loader/webpack.config.js
+++ b/examples/loader/webpack.config.js
@@ -1,4 +1,5 @@
 module.exports = {
+	mode: "production",
 	module: {
 		rules: [
 			{ test: /\.css$/, loader: "css-loader" }
diff --git a/examples/move-to-parent/webpack.config.js b/examples/move-to-parent/webpack.config.js
index f39633eae..c8cf055b6 100644
--- a/examples/move-to-parent/webpack.config.js
+++ b/examples/move-to-parent/webpack.config.js
@@ -7,12 +7,14 @@ var outputOptions = {
 };
 module.exports = [{
 	name: "page",
+	mode: "production",
 	entry: {
 		page: "./page"
 	},
 	output: outputOptions
 }, {
 	name: "pageA",
+	mode: "production",
 	entry: {
 		pageA: "./page"
 	},
@@ -26,6 +28,7 @@ module.exports = [{
 	]
 }, {
 	name: "pageB",
+	mode: "production",
 	entry: {
 		pageB: "./page"
 	},
@@ -40,6 +43,7 @@ module.exports = [{
 	]
 }, {
 	name: "pageC",
+	mode: "production",
 	entry: {
 		pageC: "./page"
 	},
diff --git a/examples/multi-compiler/webpack.config.js b/examples/multi-compiler/webpack.config.js
index b6f932f29..ef27f86df 100644
--- a/examples/multi-compiler/webpack.config.js
+++ b/examples/multi-compiler/webpack.config.js
@@ -3,6 +3,7 @@ var webpack = require("../../");
 module.exports = [
 	{
 		name: "mobile",
+		mode: "production",
 		entry: "./example",
 		output: {
 			path: path.join(__dirname, "js"),
@@ -16,6 +17,7 @@ module.exports = [
 	},
 	{
 		name: "desktop",
+		mode: "production",
 		entry: "./example",
 		output: {
 			path: path.join(__dirname, "js"),
diff --git a/examples/multi-part-library/webpack.config.js b/examples/multi-part-library/webpack.config.js
index a747606bc..d7681599d 100644
--- a/examples/multi-part-library/webpack.config.js
+++ b/examples/multi-part-library/webpack.config.js
@@ -1,5 +1,6 @@
 var path = require("path");
 module.exports = {
+	mode: "production",
 	entry: {
 		alpha: "./alpha",
 		beta: "./beta"
diff --git a/examples/multiple-commons-chunks/webpack.config.js b/examples/multiple-commons-chunks/webpack.config.js
index e1a66ea31..5c08e5c47 100644
--- a/examples/multiple-commons-chunks/webpack.config.js
+++ b/examples/multiple-commons-chunks/webpack.config.js
@@ -1,6 +1,7 @@
 var path = require("path");
 var CommonsChunkPlugin = require("../../lib/optimize/CommonsChunkPlugin");
 module.exports = {
+	mode: "production",
 	entry: {
 		pageA: "./pageA",
 		pageB: "./pageB",
diff --git a/examples/multiple-entry-points-commons-chunk-css-bundle/webpack.config.js b/examples/multiple-entry-points-commons-chunk-css-bundle/webpack.config.js
index 270426855..357232683 100644
--- a/examples/multiple-entry-points-commons-chunk-css-bundle/webpack.config.js
+++ b/examples/multiple-entry-points-commons-chunk-css-bundle/webpack.config.js
@@ -3,6 +3,7 @@ const LoaderOptionsPlugin = require("../../lib/LoaderOptionsPlugin");
 const CommonsChunkPlugin = require("../../lib/optimize/CommonsChunkPlugin");
 const ExtractTextPlugin = require("extract-text-webpack-plugin");
 module.exports = {
+	mode: "production",
 	entry: {
 		A: "./a",
 		B: "./b",
diff --git a/examples/multiple-entry-points/webpack.config.js b/examples/multiple-entry-points/webpack.config.js
index 015615814..67cdddef3 100644
--- a/examples/multiple-entry-points/webpack.config.js
+++ b/examples/multiple-entry-points/webpack.config.js
@@ -1,6 +1,7 @@
 var path = require("path");
 var CommonsChunkPlugin = require("../../lib/optimize/CommonsChunkPlugin");
 module.exports = {
+	mode: "production",
 	entry: {
 		pageA: "./pageA",
 		pageB: "./pageB"
diff --git a/examples/scope-hoisting/webpack.config.js b/examples/scope-hoisting/webpack.config.js
index da883a7c1..b913c78ab 100644
--- a/examples/scope-hoisting/webpack.config.js
+++ b/examples/scope-hoisting/webpack.config.js
@@ -1,7 +1,3 @@
-var webpack = require("../../");
-
 module.exports = {
-	plugins: [
-		new webpack.optimize.ModuleConcatenationPlugin()
-	]
+	mode: "production"
 };
diff --git a/examples/source-map/webpack.config.js b/examples/source-map/webpack.config.js
index 7f0dac899..0b73dfbef 100644
--- a/examples/source-map/webpack.config.js
+++ b/examples/source-map/webpack.config.js
@@ -13,6 +13,7 @@ module.exports = [
 	"nosources-source-map",
 	"source-map",
 ].map(devtool => ({
+	mode: "development",
 	entry: {
 		bundle: "coffee-loader!./example.coffee",
 	},
diff --git a/examples/two-explicit-vendor-chunks/webpack.config.js b/examples/two-explicit-vendor-chunks/webpack.config.js
index 3d7b5f8ad..d2c29bf69 100644
--- a/examples/two-explicit-vendor-chunks/webpack.config.js
+++ b/examples/two-explicit-vendor-chunks/webpack.config.js
@@ -1,6 +1,7 @@
 var path = require("path");
 var CommonsChunkPlugin = require("../../lib/optimize/CommonsChunkPlugin");
 module.exports = {
+	mode: "production",
 	entry: {
 		vendor1: ["./vendor1"],
 		vendor2: ["./vendor2"],
diff --git a/examples/wasm-simple/webpack.config.js b/examples/wasm-simple/webpack.config.js
index d2df12225..2a8a66b19 100644
--- a/examples/wasm-simple/webpack.config.js
+++ b/examples/wasm-simple/webpack.config.js
@@ -1,4 +1,5 @@
 module.exports = {
+	mode: "production",
 	output: {
 		webassemblyModuleFilename: "[modulehash].wasm",
 		publicPath: "js/"
diff --git a/examples/web-worker/webpack.config.js b/examples/web-worker/webpack.config.js
index 279ff0689..1d90a6229 100644
--- a/examples/web-worker/webpack.config.js
+++ b/examples/web-worker/webpack.config.js
@@ -1,5 +1,6 @@
 var webpack = require("../../");
 module.exports = {
+	mode: "production",
 	plugins: [
 		new webpack.LoaderOptionsPlugin({
 			options: {