Can't unfollow a repo that has become private.

I started following a repo when it was public. Since then it has become private. It still appears in my list of followed repos, but I can't get to the repo's page to click unfollow.

Manually typing in the /follow/ URL doesn't work either.

The repo in question is here, if it matters: http://bitbucket.org/sgraham/skulpt/overview/