UglifyJsPlugin options.exclude does not work?

When using the UglifyJsPlugin within my webpack build I get a large list of errors from my bower_components dependencies. It looks to me (from here: https://github.com/webpack/webpack/blob/master/lib/optimize/UglifyJsPlugin.js#L43) that I should be able to use something like this

new webpack.optimize.UglifyJsPlugin({
  exclude: [
    /bower_components\//
  ]
})

which continues to throw out a massive list of errors, leading me to believe they are still being parsed.

[MilosRasic]

It’s working as expected, which is processing your generated chunks rather than source files. If you want to ignore only a few modules, extract them into a separate chunk and exclude that one from UglifyJsPlugin.

[MilosRasic]

@Sawtaytoes

new webpack.optimize.UglifyJsPlugin({
	exclude: 'chunkToNotUglify',
}),