As others have said, GitHub does produce a merge commit for the PR. You can checkout that commit like so, git fetch origin +refs/pull/$N/merge && git checkout

As others have said, GitHub does produce a merge commit for the PR. You can checkout that commit like so, git fetch origin +refs/pull/$N/merge && git checkout FETCH_HEAD However, in my experience I have seen both cases where GitHub makes new merge commits when the receiving branch changes (current master) and where it does not. Due to externalities in our test suite we sometimes have "current master" break and when we push a fix we sometimes see PRs go green and sometimes they do not. I haven't figured out why we see the two different behaviors.