Can't use nested objects in bundle

[yuschick]

I am on version 5.1.1 and trying to organise my localisation bundle like the example provided in the README.

page: {
  home: {
    actions: {
      subscribe: 'Subscribe',
    }
  }
}

localize('page.home.actions.subscribe')

However, this doesn't print the message. The example in the repo shows only two levels, foo: { bar: 'bar' } }, is that the limit to nesting? Or is there additional configuration that needs to be done that I am not seeing in the docs to suppot nested objects like this?