Classic Nintendo GameCube controllers can now work with the Nintendo Switch via a USB adapter, following a version 4.0.0 system update released late last week. While Nintendo didn't list the feature in its official release notes, the new controller support was discovered and spread on Twitter yesterday, then quickly confirmed by others.

GameCube controllers show up on the Switch controller-calibration screen with a "USB" label when plugged into the system dock via Nintendo's official GameCube controller adapter , which was first released years ago alongside Super Smash Bros. for Wii U (third-party adapters may not work as well, from reports). The controllers seem to work with every available Switch game , though the GameCube controller lacks an equivalent for the Switch's "minus" and "ZL" buttons, limiting the functionality in some titles. Other USB controllers, such as wired Xbox 360 game pads, still aren't recognized when plugged into the Switch.

The surprise controller addition will be welcome news for the many longtime Nintendo fans who think Nintendo never really improved on the oddly shaped GameCube controller design and for those who want to use bigger analog sticks on the system without having to invest in the Switch Pro Controller.

The feature's stealth launch is already fueling speculation that Nintendo may be planning support for downloadable GameCube games on the Switch's still-pending Virtual Console . GameCube controller support would also practically be a prerequisite for getting serious players to support any upcoming Super Smash Bros. game for the Switch, should Nintendo ever see fit to announce one. Hmm...