It’s been possible to close an issue from a commit for quite a while, but
some issues take more work than a single commit to close. That’s why you
can now close an issue from a Pull Request. All you have to do is include the
special keyword syntax (eg. “fixes #5”) in the body of your Pull Request.

And the referenced issue will automatically be closed when the PR is merged
into the default branch.

You will even see the references as pending fixes before merging.

This works the same way closing an issue from a commit message does.
It even works across repositories.

Happy bug fixing!