Sony might not be ready to unveil the PlayStation 5, but the company has already made several announcements about its next-gen console. We already know what sort of performance upgrades to expect from the hardware, and Sony previously revealed the significant haptic improvements coming to the PS5 controller, which will probably be called DualShock 5. But a new discovery indicates that the device might have a few additional features that aren’t available on DualShock 4, and Sony might not be ready to reveal them just yet.

Dutch-language blog LetsGoDigital found a Sony patent application dated June 20th, 2019 that was published online on December 26th. The documentation details the functionality of a PlayStation controller that features extra buttons on the back.

If this sounds familiar in any way, that’s because Sony just announced a DualShock 4 accessory, the Back Button Attachment (image above), that lets you add user-configurable buttons to the back of the current controller. That’s the kind of attachment that should be built into future versions of the controller, especially the DualShock 5.

Image Source: Sony via LetsGoDigital

On the back, the patent describes four buttons, two buttons on each side that are built into the controller. The large button moves up and down, apparently. The smaller button can be controlled by pressing it. The larger one can extend the handles, the report notes, allowing you to customize the length of the handles to better fit your hands for improved grip during gameplay, as suggested in the following image.

Image Source: Sony via LetsGoDigital

The smaller button packs a pressure sensor that will be able to tell how hard you press it and trigger an appropriate action on the screen.

As always with new patents, the technology they describe won’t necessarily make it into next-gen products. However, the Back Button Attachment for DualShock 4 does prove that Sony thinks the PlayStation controller needs buttons on the back for better gameplay. Considering the PS5 is supposed to be better than its predecessor in every way and also run PS4 games, it makes sense to see the DualShock 5 come with built-in back buttons that won’t require the purchase of an attachment.