Fortnite” maker Epic Games said it filed an antitrust lawsuit against Google and Samsung, alleging that the tech giants secretly colluded and imposed “onerous” restrictions on new third-party app stores.

While it’s turned on, it automatically keeps users from installing apps unless they come from “authorized sources” — namely, Google and Samsung’s app stores. Epic claims there’s no process for any rival store to become “authorized.

Video game maker Epic Games sued Google and Samsung on Monday, accusing the tech companies of coordinating to block third-party competition in application distribution on Samsung devices.