A Microsoft patent filed last month revealed plans for controllers that will transform smartphones into handheld Xbox consoles, in what may be the system’s first foray into gaming on the go.

The patent, filed on July 9, is for a charging device for removable input modules. While there is no specific mention of the Xbox in the application, a couple of the drawings feature all-too-familiar buttons and symbols.

The patent is specifically for the charger of the controllers, which the filing said will temporarily attach to a touchscreen device to provide input controls. Possible features for the controllers include built-in speakers, a headphone jack, and wireless headphones support.

The controllers will address certain issues commonly experienced in games for a touchscreen device such as a smartphone, including slipping fingers, obscured parts of the display, and the cramped space for on-screen controls.

The controllers featured on the Microsoft patent may make Project xCloud more attractive to smartphone gamers, as it will enable on-the-go gaming for Xbox exclusives like the upcoming Gears 5.

This will not be Microsoft’s first attempt at entering the handheld gaming market though. A few years ago, Microsoft’s former Chief Xbox Officer Robbie Bach revealed that the “Xboy” project was in development. However, the device did not leave the conceptual stages before it was ultimately scrapped.

With the detachable controllers just part of a patent, and without an official announcement from Microsoft, it remains to be seen how long players will need to wait for a handheld Xbox if it will arrive at all.