When examining the code of the Wii version of Super Mario Bros., a game originally released for the Nintendo Entertainment System (NES) console in 1985, game developer Frank Cifaldi noticed that some of it matched a file developed by Marat Fayzullin, an early game emulator in the 1990s. (Emulated games are born when tinkerers make versions of games designed to run on computers other than the consoles Nintendo designed them for.)

Back then, Fayzullin realized that to make NES games run on a computer, you needed to build a “header”—essentially a piece of descriptive code that appears on every file. Today he confirmed to Eurogamer that the header in the code for Nintendo’s Super Mario Bros. for Wii matches the one he created decades ago.

That’s pretty ironic, considering Nintendo’s website refers to emulated games as “the greatest threat to date to the intellectual property rights of video game developers.”

Nintendo wasn’t immediately available to comment, but the company told Eurogamer that the emulation program it used to develop Super Mario Bros. for Wii was created internally, and didn’t rely on downloads from the internet.

Even if Nintendo didn’t just download an emulated copy of Super Mario Bros. from the internet and sell it to customers, developing emulators internally while maintaining an anti-emulator stance publicly is still a bit hypocritical. Especially considering that up until 2016, it was near-impossible to find any Nintendo-related games on non-Nintendo platforms. Last year, Nintendo did help create a mobile version of its popular Pokémon game, as well as a Mario game for the iPhone. But if you want to play Super Mario Bros. on your phone, computer, or tablet, you’re still going to have to do it illegally.

📬 Sign up for the Daily Brief

Our free, fast, and fun briefing on the global economy, delivered every weekday morning.