Why does Xcode not show my custom documentation in the autocomplete popup?

Question

I'm using Xcode 8.1, a simple Swift app with a custom class. I added documentation using ///, but it is not showing in the autocompletion popup.

However, it does show in the Quick Help sidebar and the Quick Help popup so the documentation is recognized by Xcode.

The autocomplete popup is the most important tool for me. I'd like the documentation to show there as well. How can I do that? (I tried restarting Xcode, clean/rebuild, etc.)

Source code:

class Person {
    /// Says "Hi!"
    func sayHi() {
    }
}