Nintendo released Donkey Kong 64 in 1999, which means gaming enthusiasts have had plenty of time to perfect their run-throughs. Collecting every last one of the game’s 976 banana coins is no small feat, but Twitch user Isotarge recently achieved something even more impressive. As Kotaku reports, the speedrunner uncovered a 977th coin that’s been hidden in the game’s code for more than 17 years.

The treasure was able to go unnoticed for so long because it’s located in a confusing area. Players normally uncover rainbow coins—the most valuable currency in the game—by pounding on patches of dirt. In the Fungi Forest level, this giveaway dirt patch is concealed by a layer of tall grass.

The bonus coin is so well hidden that the player who found it only became aware of it while combing through the game’s save data. After finishing what was thought to be a full run of the Fungi Forest stage, the player noticed the Rainbow Coin count wasn’t quite complete. Instead of replaying the level blindly, they used analysis tools to identify the coin’s exact location and dig it up.

It’s not unheard of for years to go by before a hidden video game feature is finally discovered. When programmer Landon Dyer slipped his initials into the code of 1983’s Donkey Kong, it went unnoticed for 26 years. But unlike some trickier video game Easter eggs, the 977th rainbow coin is actually part of its game. That’s sure to annoy many perfectionist speedrunners.

[h/t Kotaku]