Tapbots, the development team behind the popular Tweetbot Twitter client for Mac and iOS have issued a mandatory update for all users. According to a post on the Tapbots blog, all current mobile versions of the app will cease to function soon due to a change in the app requested by Twitter.

Updates for both iPhone versions of the app are rolling out now. Users on iOS 6 running Tweetbot 2 can look out for version 2.8.8, while users on the newer Tweetbot 3 can already find version 3.3.2 in the App Store. The Mac and iPad versions of the app aren’t mentioned in the post, so it’s possible they won’t need to be updated. (Update: The iPad version has been updated to version 2.8.8 as well.)

According to the post, the changes will take effect on May 29th at 10 AM Pacific time. At that time older versions of the app will stop working and users might need to re-add their accounts to the apps to continue using them.