While the Nintendo Switch Pro Controller is styled like any other console controller, the apparatus’ housing is made from a tinted transparent plastic which reveals a small Easter egg in the form of a string of code. First reported in 2017 when the console hit the shelves, some owners of the Pro Controller soon found a secret hidden behind one of the joysticks.

Printed in white letters inside the housing is the code, “THX2ALLGAMEFANS,” meaning “Thanks to all game fans.” The message appears to be a sentiment shared by Nintendo to everyone who has purchased its consoles and played Nintendo games. The phrase can only be seen if the controller is held at the right angle and the right joystick is pulled down.

The code appears within the small gap that opens up when the joystick is moved out of the way, but you’ll likely need to be in a well-lit room. It appears that only the regular Nintendo-branded Pro Controller features the Easter egg, while other versions of the controller, like those released with themes related to new games, don’t have the same hidden phrase.