Cannot retract a single handed close vote

I just close voted a question and as I have enough privilege, the qustion was immediately closed.So far so good.

But then I realized that I shouldn't have close voted, but it's impossible to retract the close vote. I can edit the close vote and remove the duplicate, but then the "Save" button remains inactive.

IMO the Save button should be active in that case.

I'm not sure if this is a bug or a feature.