diff --git a/plugins/add-vendors-plugin.js b/plugins/add-vendors-plugin.js
index 76e4a09..8ed1071 100644
--- a/plugins/add-vendors-plugin.js
+++ b/plugins/add-vendors-plugin.js
@@ -18,9 +18,9 @@ module.exports = class AddVendorsPlugin {
                 const vendor = compilation.assets[`vendors.${this.base}`]
 
                 if (main && vendor) {
-                    const compiledAsset = new ConcatSource(main.children[0])
+                    const compiledAsset = new ConcatSource(main._value[0])
                     compiledAsset.add(vendor)
-                    compiledAsset.add(main.children[1])
+                    compiledAsset.add(main._value[1])
                     compilation.assets = {}
                     compilation.assets[this.base] = compiledAsset
                 } else if (main && mainMap) {
@@ -28,6 +28,7 @@ module.exports = class AddVendorsPlugin {
                     compilation.assets[this.base] = main
                     compilation.assets[`${this.base}.map`] = mainMap
                 }
+                
                 callback()
             }
         )
diff --git a/webpack.development.js b/webpack.development.js
index 4b2751e..e60bb0b 100644
--- a/webpack.development.js
+++ b/webpack.development.js
@@ -6,29 +6,29 @@
 
 'use strict'
 
-const UglifyJsPlugin = require('uglifyjs-webpack-plugin')
+const TerserPlugin = require('terser-webpack-plugin')
 
 module.exports = {
-    devtool: 'inline-source-map',
-    optimization: {
-        minimizer: [
-            new UglifyJsPlugin({
-                test: /vendor/,
-                sourceMap: false,
-            }),
-            new UglifyJsPlugin({
-                test: /^((?!(vendor)).)*.js$/,
-                sourceMap: true,
-            })
-        ],
-        splitChunks: {
-            cacheGroups: {
-                commons: {
-                    test: /[\\/]node_modules[\\/]/,
-                    name: 'vendors',
-                    chunks: 'all'
-                }
-            }
-        },
-    },
+  devtool: 'inline-source-map',
+  optimization: {
+    minimizer: [
+      new TerserPlugin({
+        test: /vendor/,
+        sourceMap: false
+      }),
+      new TerserPlugin({
+        test: /^((?!(vendor)).)*.js$/,
+        sourceMap: false
+      })
+    ],
+    splitChunks: {
+      cacheGroups: {
+        commons: {
+          test: /[\\/]node_modules[\\/]/,
+          name: 'vendors',
+          chunks: 'all'
+        }
+      }
+    }
+  }
 }
diff --git a/webpack.parts.js b/webpack.parts.js
index 7407ee4..bbc8436 100644
--- a/webpack.parts.js
+++ b/webpack.parts.js
@@ -7,7 +7,7 @@
 'use strict'
 
 const path = require('path')
-const merge = require('webpack-merge')
+const { merge } = require('webpack-merge')
 
 const development = require('./webpack.development.js')
 const production = require('./webpack.production.js')