Nintendo might be working on a new version of the Switch’s Joy-Con. It filed documents with the Federal Communications Commission last week that include photos of the controller and its internals, along with a radio test report stating the device is still FCC compliant.

When Nintendo Switch launched in March 2017, many complained their left Joy-Con would desync and stop functioning while not attached to the console. At the time, Nintendo blamed a “manufacturing variation” that caused wireless interference in a small number of controllers. It offered some suggestions, like not standing too far away from the Switch or, oddly, not operating it around an aquarium or metal objects. It also released a number of software patches to address the issue, but there’s only so much software can do to fix a hardware defect.

Nintendo later said in a statement the problem was corrected at the factory level and wouldn’t be an issue going forward. “We have determined a simple fix can be made to any affected Joy-Con to improve connectivity,” it said. That simple fix, according to CNET, was a little piece of conductive black foam that shields the device from RF interference.

Now, it appears Nintendo is creating a more permanent solution. The FCC documents mention changes to the controller’s antenna pattern and peripheral circuit, which will hopefully fix the connectivity issue for good.

Variety has contacted Nintendo to confirm whether or not it’s working on an updated Joy-Con and why.