A California-based manufacturer of a detachable games console has sued video game giant Nintendo this week over an alleged case of patent infringement. Gamevice turn tablet computers into portable gaming devices and have owned the patent for the “Combination Computing Device and Game Controller with Flexible Bridge Section” in 2015.

The lawsuit claims it is the controllers for the new Nintendo Switch that infringe on their proprietary design and Gamevice are seeking damages, as well as demanding Nintendo immediately stop selling and creating the consoles. Nintendo has sold 4.7 million Switch units since March, its latest earning report says. Each is sold with a pair of controllers.

Furthermore, the lawsuit claims that the design of the Switch infringes on the patent for the plaintiffs’ device, also called the Gamevice. Each employs two controllers that attach and detach from a tablet computer, allowing gamers to use traditional buttons and joysticks to control play instead of using the device’s touchscreen.

There are some similarities between the two products, but, given that Nintendo seems to be equally diligent about filing patents for its various devices, Gamevice may find it has a difficult road ahead.

Nintendo did not immediately respond to the suit.