Apple’s quest to make ever thinner devices faces one major obstacle: the 3.5mm audio jack. The company’s already pushing the limits of how slim it can go without ditching that key component entirely, but a new patent could make it possible to keep a separate audio jack while shaving a a few more millimeters off future iPhones and iPads.

The Cupertino company’s patent for a “D-shaped connector” was granted this week, though it was actually filed way back in 2011. It describes a redesigned audio plug with a half-flattened shape instead of the usual full circle. The result is a significantly thinner design.

Apple notes that the new jack design would offer a “smooth, consistent feel” when you insert your headphones. The new plug might also use a flexible material to avoid any issues during insertion. That could increase the lifespan of your future EarPods overall by limiting daily wear and tear.

We assume that you’d be able to plug Apple’s D-shaped plug into a traditional audio jack. However, the opposite probably won’t be true. Headphone-makers may need to adopt Cupertino’s new design or offer some sort of extra adapter.

Of course there’s no guarantee Apple will actually go through with this plan. A year after filing this patent the company introduced its super-thin Lightning port, which looks primed to replace the audio jack altogether… if Bluetooth doesn’t.