diff --git a/app.config.environment.dev.js b/app.config.environment.dev.js
new file mode 100644
index 0000000000000000000000000000000000000000..14d6a3ca2d7e62b290d3234b7695e35998c89cf0
--- /dev/null
+++ b/app.config.environment.dev.js
@@ -0,0 +1,54 @@
+'use strict'
+
+const webpack = require('webpack')
+const merge = require('webpack-merge')
+const { useHotReload, devtool } = require('./webpack.vars')
+
+let plugins = [
+  new webpack.DefinePlugin({
+    __DEVELOPMENT__: true,
+  }),
+]
+
+// In development, the bar and cozy-client-js are provided automatically. We use the ProvidePlugin
+// since it allows us to use in production the cozy.bar and cozy.client declared by the <script />
+// line injected by the stack, while in developement to have it "served" from
+// our node_modules
+const stackProvidedLibsConfig = {
+  plugins: [
+    new webpack.DefinePlugin({
+      __STACK_ASSETS__: true,
+    }),
+  ],
+  module: {
+    rules: [
+      {
+        test: /cozy-bar\/dist\/cozy-bar\.min\.js$/,
+        // Automatically import the CSS if the JS is imported.
+        // imports-loader@0.8.0 works but imports-loader@1.0.0 does not
+        loader: 'imports-loader?css=./cozy-bar.min.css',
+      },
+    ],
+  },
+}
+
+const output = {}
+if (useHotReload) {
+  plugins = plugins.concat([new webpack.HotModuleReplacementPlugin()])
+  output.globalObject = 'this'
+}
+
+module.exports = merge(
+  {
+    devtool: devtool || 'cheap-module-eval-source-map',
+    mode: 'development',
+    externals: ['cozy'],
+    plugins,
+    output,
+    optimization: {
+      removeAvailableModules: false,
+      removeEmptyChunks: false,
+    },
+  },
+  stackProvidedLibsConfig
+)
diff --git a/app.config.js b/app.config.js
index 21d137b224ff8a6abcce6759d71ff6716667402e..441171d42eb34c5c72e4b582ac533ce71f8ee43e 100644
--- a/app.config.js
+++ b/app.config.js
@@ -33,9 +33,9 @@ const configs = [
 ]
 
 if (environment === 'production') {
-  configs.push(require('cozy-scripts/config/webpack.environment.prod'))
+  configs.push(require('./app.config.environment.dev'))
 } else {
-  configs.push(require('cozy-scripts/config/webpack.environment.dev'))
+  configs.push(require('cozy-scripts/config/webpack.environment.prod'))
 }
 
 //module.exports = merge.apply(null, configs)