A bug that was live between May 29 and June 5 allowed blocked users to see the profile pages of people that blocked them and send them messages through Messenger, Facebook revealed Monday. The issue affected more than 800,000 users on the platform. About 83% of those Facebook users had one person they blocked essentially unblocked by the bug, while 17% had more than one blocked person unblocked during that time period, the social network said.

Facebook has contacted the users that were impacted by the issue.

It’s worth noting that the issue didn’t give previously blocked users full access to someone’s account. Instead, they would simply have been able to see things that were posted publicly on the platform. When you block someone on Facebook you also unfriend them (presuming you were friends in the first place). The bug did not reinstate any of those ended connections.

Facebook says that it has corrected the issue, and everyone who you previously blocked is now fully blocked again. If you want to see who is currently on your blocked list, you can do that by clicking here.