Cannot remove groups from jira project because it's been deleted

[Marijn Vandevoorde]

So, in the project's settings "people" tab, there are some groups that no longer exist. I cannot delete them. I get a lovely error message saying the group does not exist in the system. I'd expect the group to be deleted automatically if that's the case since it makes no sense for it to be there, right? Not right apparently... 

Do I have to re-create the groups, delete them from all these projects and then delete them again?

Or is there a more user friendly way?