Nice. It looks like this pull request is for a specific commit, not a branch, so you might have to create a new one and then close this one (leaving a comment pointing to the new one, e.g. "Reopened as \#xx").

I suggest creating a new branch in your repository for this specific pull request (e.g. "response-headers") and then creating the new pull request from that. That way, if you need to make more changes they'll be automatically included. The pull request should look like "into `loopj:master` from `rustybox:response-headers`" instead of `rustybox:d8f606c`.

I've made the same mistake in the past; maybe someday github will let you rebase pull requests…