Looks like it was fixed a week ago?

https://github.com/doorkeeper-gem/doorkeeper/commit/c1b5c45e...

Oops, I deleted the comment. I had filed a bug[1], without realizing 2.0.0 was released a few hours ago with the fixes in it.

https://github.com/doorkeeper-gem/doorkeeper/issues/524

Right. When Sergey Belove originally reported this to DigitalOcean, one of our engineers reported and fixed this in upstream Doorkeeper.