How to restrict pull request approval

Someone who has recently made valuable contributions to one of my projects has approved a pull request coming from someone else and added a (slightly weird and easy to misunderstand) comment. This might have made it seem like this was an official approval (and official weird comment) from one of the maintainers.

I like this person and don’t want to discourage him from contributing, but I as the sole maintainer and owner of the repo, want to be the only one who is able to approve a PR.

Is there a config setting for this that I have missed? Or does someone who has ever contributed to the repo gain approval privileges?

EDIT: I understand that this person doesn’t have write access and his approval does not count towards mergeability, as the help text says. Still, I find it very weird that basically, random people can approve PRs.

Yes basically anyone can approve a PR, however that approval should have a different coloured icon.

Further as the repo owner you should be able to edit or delete the comment or even the approval for that matter.

Of course you can always add a follow-up comment clarifying that “John Doe” has no authority to approve PRs and while his input is appreciated you still feel items xyz are still outstanding (or whatever).

Thank you. The follow-up comment is a good idea! Marking this as solved.