Error webpack using sass loader

Currently I'm stuck on getting Sass to work in my React project. In the guide I followed everything is working fine but as soon as I get to the point where I need to use the ExtractTextPlugin in my webpack.config.js it throws me an error. My main sass file is located in root/style.main.scss and is included in my index.js where it renders my app in the DOM like this: import style from '../style/main.scss';

webpack.config.js:

module.exports = {
  entry: './src/index.js',
  output: {
    path: __dirname,
    filename: 'bundle.js'
  },
  module: {
    loaders: [
      {
        test: /.jsx?$/,
        loader: 'babel-loader',
        exclude: /node_modules/,
        query: {
          presets: [
            'es2015',
            'react'
          ]
        }
      },
      { test: /\.css$/, exclude: /\.useable\.css$/, loader: "style!css" },
      { test: /\.useable\.css$/, loader: "style/useable!css" },
      // sass
      {
        test: /\.scss$/,
        loader: ExtractTextPlugin.extract('css!sass')
      }
    ]
  },
  plugins: [
        new ExtractTextPlugin('public/style.css', {
            allChunks: true
        })
  ],
  resolve: {
    extensions: ['', '.js', '.jsx']
  },
  devServer: {
    proxy: {
      '/api/*': {
        target: 'http://mab-cmdb.dev',
        secure: false,
        changeOrigin: true
      }
    }
  },
};

EDIT: webpack error

/Users/jordykoppen/git/mab-cmdb-v2-frontend/webpack.config.js:25
        loader: ExtractTextPlugin.extract('css!sass')
                ^

ReferenceError: ExtractTextPlugin is not defined
    at Object.<anonymous> (/Users/jordykoppen/git/mab-cmdb-v2-frontend/webpack.config.js:25:17)
    at Module._compile (module.js:409:26)
    at Object.Module._extensions..js (module.js:416:10)
    at Module.load (module.js:343:32)
    at Function.Module._load (module.js:300:12)
    at Module.require (module.js:353:17)
    at require (internal/module.js:12:17)
    at module.exports (/usr/local/lib/node_modules/webpack-dev-server/node_modules/webpack/bin/convert-argv.js:80:13)
    at Object.<anonymous> (/usr/local/lib/node_modules/webpack-dev-server/bin/webpack-dev-server.js:62:48)
    at Module._compile (module.js:409:26)

Thanks for the help.