Apple has secured a patent to produce its own small mountable sports camera, causing GoPro’s stock to take a significant tumble on Tuesday.

GoPro’s stock lost 12% of its value, down $6.91 a share, as news emerged from blog Patently Apple of details of the camera.

The device, which is designed to be attached to a helmet, handlebars or surfboards, uses underwater and controlled remotely with a smartwatch, like the upcoming Apple Watch.

Apple has not announced plans to produce a GoPro rival, and just having a patent doesn’t mean it ever will. Companies like Apple routinely secure numerous patents that don’t result in products.

But the patent, issued by the United States Patent and Trademark Office, and whose application was originally filed in 2012, specifically mentions GoPro, which clearly sent shivers up the spines of shareholders and traders on Wall Street.

In the documents, Apple notes that the design of GoPro’s HD Hero2 camera creates “excessive wind resistance” and is “susceptible to damage” from vibrations when mounted.

The patent also includes another that Apple purchased from Kodak when the camera company went bankrupt in 2013.

As its brand continues to take off with sports enthusiasts and broaden into more of a full-fledged entertainment company, GoPro is facing increased competition from other consumer electronics manufacturers.

Sony used last week’s Consumer Electronics Show in Las Vegas to promote its new Action Cam, which now records in 4K HD video, while LG and Polaroid have cheaper versions for non-pros.

GoPro’s stock has lost half its value since its peak in October.