Webpack CommonJS Named Exports

I have a simple library like so:

export const foo = () => {
  console.log("Hello")
}

I am trying to use Webpack to bundle it to CommonJS like so:

module.exports.foo = () => {
  console.log("Hello")
}

My webpack config is simple:

module.exports = {
  entry: {
    index: "./src-test"
  },
  output: {
    filename: "[name]-bundle.cjs.js",
    libraryTarget: "commonjs2"
  }
}

However, it's getting bundled under the default namespace like so:

module.exports = function (e) {
// ...

Why is this happening and how can I use named exports?