Настройка Webpack ExtractTextPlugin

Не могу понять какой publicPath указать для extract-text-webpack-plugin чтобы подгрузить стили при запуске webpack-dev-server.

const PATH = require('path');
const CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const PATHS = {
  source: PATH.join(__dirname, 'js'),
  build: PATH.join(__dirname, 'build/js'),
};
const conf = {
  context: PATHS.source,
  entry: {
    index: './main.js',
  },
  output: {
    filename: '[name].js',
    path: PATHS.build,
    publicPath: '/build/js', // required for webpack-dev-server
  },
  plugins: [
    new CaseSensitivePathsPlugin(),
    new ExtractTextPlugin('../css/style.css'),
  ],
  devServer: {
    overlay: true,
    contentBase: PATH.join(__dirname),
    watchContentBase: true,
    watchOptions: {
      poll: true,
    },
  },
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: ExtractTextPlugin.extract(
          {
            fallback: 'style-loader',
            use: ['css-loader', 'sass-loader'],
            publicPath: '/build/css',
          },
        ),
      },
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: 'babel-loader',
      },
      {
        test: /\.(png|jpg|gif)$/,
        use: [
          {
            loader: 'file-loader',
            options: {
              outputPath: '../img',
            },
          },
        ],
      },
      {
        test: /\.svg$/,
        loader: 'svg-inline-loader',
      },
    ],
  },
};
module.exports = (env, argv) => {
  conf.devtool = argv.mode === 'development' ? 'source-map' : false;
  // source-map was choosen because css-loader source-map don't work with eval
  return conf;
};