lmarburger/mime-types — comment on commit 452db4d62e43e9f13c4f8c819f5f5728297960ab
File:  line 0
By halostatue:

This sort of change should be made to the data after loading MIME::Types and not by modifying the source data. mp4 has been added to video/mp4, but remains on vnd.objectvideo for the upcoming 1.18 release.