An updated version of Microsoft’s Surface Pen, which is expected to be announced at the company’s annual fall hardware event on October 2nd, may come with wireless charging. An FCC filing for the stylus refers to a “charging coil,” pointing to the possibility that the pen will have an internal power source, allowing for it to be used without AAAA batteries like the pen’s current model does.

Teardowns for competitor styluses with wireless charging have revealed coils being used for this exact purpose. In this JerryRigEverything teardown of the Galaxy Note 10 Plus’ S-Pen, a charging coil can be found toward the tip of the pen, showing how the pen is charged through the phone.

The Apple Pencil 2, which charges by magnetically attaching to the side of an iPad Pro, sports a similar charging coil. You can check it out in the photo below from the iFixit teardown. The Surface Pen already magnetically attaches to Surface laptops, albeit without charging, so hopefully this FCC filing is a sign of the feature to come.

The upcoming Surface Pen will likely be another separately purchased accessory priced at around $99 to accompany the new Surface Pro line. We should learn more details about it during Microsoft’s fall event on October 2nd.