diff --git a/package.json b/package.json
index 25f300d5f4b..131bd110c91 100644
--- a/package.json
+++ b/package.json
@@ -59,6 +59,7 @@
   },
   "homepage": "http://rackt.github.io/redux",
   "dependencies": {
+    "lodash": "^4.1.0",
     "loose-envify": "^1.1.0"
   },
   "devDependencies": {
diff --git a/src/combineReducers.js b/src/combineReducers.js
index 9569f0cffec..84bdc28f18a 100644
--- a/src/combineReducers.js
+++ b/src/combineReducers.js
@@ -1,5 +1,5 @@
 import { ActionTypes } from './createStore'
-import isPlainObject from './utils/isPlainObject'
+import isPlainObject from 'lodash/isPlainObject'
 import warning from './utils/warning'
 
 function getUndefinedStateErrorMessage(key, action) {
diff --git a/src/createStore.js b/src/createStore.js
index befa312882f..c422b51ad67 100644
--- a/src/createStore.js
+++ b/src/createStore.js
@@ -1,4 +1,4 @@
-import isPlainObject from './utils/isPlainObject'
+import isPlainObject from 'lodash/isPlainObject'
 
 /**
  * These are private action types reserved by Redux.
diff --git a/src/utils/isPlainObject.js b/src/utils/isPlainObject.js
deleted file mode 100644
index 3921c3045c8..00000000000
--- a/src/utils/isPlainObject.js
+++ /dev/null
@@ -1,24 +0,0 @@
-var fnToString = (fn) => Function.prototype.toString.call(fn)
-var objStringValue = fnToString(Object)
-
-/**
- * @param {any} obj The object to inspect.
- * @returns {boolean} True if the argument appears to be a plain object.
- */
-export default function isPlainObject(obj) {
-  if (!obj || typeof obj !== 'object') {
-    return false
-  }
-
-  var proto = typeof obj.constructor === 'function' ? Object.getPrototypeOf(obj) : Object.prototype
-
-  if (proto === null) {
-    return true
-  }
-
-  var constructor = proto.constructor
-
-  return typeof constructor === 'function'
-    && constructor instanceof constructor
-    && fnToString(constructor) === objStringValue
-}
diff --git a/test/utils/isPlainObject.spec.js b/test/utils/isPlainObject.spec.js
deleted file mode 100644
index 3314c5ff6e4..00000000000
--- a/test/utils/isPlainObject.spec.js
+++ /dev/null
@@ -1,22 +0,0 @@
-import expect from 'expect'
-import isPlainObject from '../../src/utils/isPlainObject'
-import vm from 'vm'
-
-describe('isPlainObject', () => {
-  it('returns true only if plain object', () => {
-    function Test() {
-      this.prop = 1
-    }
-
-    const sandbox = { fromAnotherRealm: false }
-    vm.runInNewContext('fromAnotherRealm = {}', sandbox)
-
-    expect(isPlainObject(sandbox.fromAnotherRealm)).toBe(true)
-    expect(isPlainObject(new Test())).toBe(false)
-    expect(isPlainObject(new Date())).toBe(false)
-    expect(isPlainObject([ 1, 2, 3 ])).toBe(false)
-    expect(isPlainObject(null)).toBe(false)
-    expect(isPlainObject()).toBe(false)
-    expect(isPlainObject({ 'x': 1, 'y': 2 })).toBe(true)
-  })
-})
diff --git a/webpack.config.base.js b/webpack.config.base.js
index 0dd203db37a..0d1b556c973 100644
--- a/webpack.config.base.js
+++ b/webpack.config.base.js
@@ -1,5 +1,7 @@
 'use strict';
 
+var webpack = require('webpack');
+
 module.exports = {
   module: {
     loaders: [
@@ -10,7 +12,7 @@ module.exports = {
     library: 'Redux',
     libraryTarget: 'umd'
   },
-  resolve: {
-    extensions: ['', '.js']
-  }
+  plugins: [
+    new webpack.optimize.OccurenceOrderPlugin()
+  ]
 };
diff --git a/webpack.config.development.js b/webpack.config.development.js
index e509d7cd245..3c0a1d97356 100644
--- a/webpack.config.development.js
+++ b/webpack.config.development.js
@@ -1,14 +1,13 @@
 'use strict';
 
+var _ = require('lodash');
 var webpack = require('webpack');
 var baseConfig = require('./webpack.config.base');
 
-var config = Object.create(baseConfig);
-config.plugins = [
-  new webpack.optimize.OccurenceOrderPlugin(),
-  new webpack.DefinePlugin({
-    'process.env.NODE_ENV': JSON.stringify('development')
-  })
-];
-
-module.exports = config;
+module.exports = _.merge({}, baseConfig, {
+  plugins: baseConfig.plugins.concat(
+    new webpack.DefinePlugin({
+      'process.env.NODE_ENV': '"development"'
+    })
+  )
+});
diff --git a/webpack.config.production.js b/webpack.config.production.js
index f4589cc06db..9cad002cd42 100644
--- a/webpack.config.production.js
+++ b/webpack.config.production.js
@@ -1,20 +1,22 @@
 'use strict';
 
+var _ = require('lodash');
 var webpack = require('webpack');
 var baseConfig = require('./webpack.config.base');
 
-var config = Object.create(baseConfig);
-config.plugins = [
-  new webpack.optimize.OccurenceOrderPlugin(),
-  new webpack.DefinePlugin({
-    'process.env.NODE_ENV': JSON.stringify('production')
-  }),
-  new webpack.optimize.UglifyJsPlugin({
-    compressor: {
-      screw_ie8: true,
-      warnings: false
-    }
-  })
-];
-
-module.exports = config;
+module.exports = _.merge({}, baseConfig, {
+  plugins: baseConfig.plugins.concat(
+    new webpack.DefinePlugin({
+      'process.env.NODE_ENV': '"production"'
+    }),
+    new webpack.optimize.UglifyJsPlugin({
+      compressor: {
+        pure_getters: true,
+        unsafe: true,
+        unsafe_comps: true,
+        screw_ie8: true,
+        warnings: false
+      }
+    })
+  )
+});