DolphiniOS, a fork of the popular Dolphin emulator for Nintendo Wii and GameCube games, has confirmed that it’s not coming to the Apple App Store even though emulators are now supported. In a post on Friday, the developer behind the emulator says it’s because Apple doesn’t allow DolphiniOS to use its underlying performance-boosting tech.

As explained by developer OatmealDome, DolphiniOS — along with other Wii and GameCube emulators — uses something called Just-in-Time (JIT). This is a compiler that “translates” the GameCube and Wii’s PowerPC-based code into a language other devices can understand, making emulations run a lot smoother.

But Apple doesn’t allow third-party apps to use JIT compilers, as noted by OatmealDome. “The only exceptions are Safari and alternative web browsers in Europe,” the developer writes. “We submitted a DMA [Digital Markets Act] interoperability request to Apple for JIT support, but Apple denied the request a few weeks ago.”

Although there’s a way to get around JIT by using an “interpreter,” OatmealDome writes that it’s “many times slower than the JIT compiler.” A pair of videos shared by OatmealDome shows just how poorly a Mario Kart Wii emulation performs on an iPhone 15 when using an interpreter instead of JIT. The Verge reached out to Apple with a request for more information about its rules surrounding JIT but didn’t immediately hear back.