Apple’s “Sign In with Apple” login system will not work with Epic Games accounts as soon as September 11th, Epic said today.

This latest development in the form of new restrictions is another casualty of Apple and Epic’s ongoing spat. If you are already using “Sign In with Apple” for your Epic account, Epic says you’ll get to update your account with new login credentials before September 11th to retain access. Epic has put together a guide describing a way to make that update if you would like to try to do so. Epic also says that it’s going to be ready to recover your account manually after the “Sign in with Apple” option goes away, but you’ll need to contact the studio directly.

Apple entails developers to use its single sign-on system if they provide the other third-party options and need their apps within the App Store — presumably, a driving factor behind Epic offering the service as sign-in thinking about the primary place.

Epic tweeted about the upcoming change on a variety of its Twitter accounts, including the most Epic Games account, the Fortnite Status account, and the Unreal Engine 5 account. That wide breadth is perhaps because Epic Games accounts span quite just letting you play the studio’s blockbuster Fortnite — they’re also want to log into the Epic Games Store, access Epic’s developer portal, and more.

It’s also worth noting that Fortnite, which is out there across many platforms, is hottest on iOS. Epic said during a legal filing last week that it’s 116 million registered users on iOS, which accounts for nearly a 3rd of the 350 million total registered Fortnite users. If even a fraction of these users believes “Sign in with Apple” and don’t change their login credentials in time, there’s an opportunity that a lot of people could lose access to their accounts.

Fortnite was banned by Apple from the App Store on August 13th when Epic introduced an in-app payment system that violated Apple’s rules. Since then, both companies are fighting a legal battle over the longer terms of Fortnite within the store as well as Epic’s standing with Apple as a developer. Epic won a short-lived restraining order on August 25th that prevented Apple from terminating Epic’s developer account utilized in conjunction with its Unreal Engine, but that order didn’t force Apple to bring Fortnite back to the App Store.