Hi, Is there a way for each person on the credits for a movie to have the imdb_id field?

This is what I'm calling:

https://api.themoviedb.org/3/movie/999?append_to_response=external_ids,credits&api_key=xxx

I know I can call the /person/person_id endpoint, but I just need that ONE extra fields and really would love to not have to make another API call.