Should `jekyll serve --watch` follow symlinks?

I’m not sure if I’m seeing a bug or expected behavior. I have a directory that’s symlinked to a location outside of where I’m running jekyll serve from. Here’s a rough sketch:

    additional -> /additional/

I’m running jekyll serve --watch from within /site/. It can see and serve the files inside of additional, but it doesn’t seem to trigger a rebuild if is changed.

Is this by design?

I’m running Jekyll 4.0.0. For background on what I’m trying to do, see this pull request.