The FTC says that the six companies’ warranties illegally condition coverage based on the use of third-party products or third-party services. The warranties also require customers to keep their warranty and to make sure the warranty sticker is not defaced or altered in any way. Those types of restrictions are only allowed if the companies offer those parts or services for free or if they receive a waiver from the FTC. The FTC will review the companies’ websites after 30 days, and if appropriate changes are not made, they can be met with law enforcement action.

The FTC did not release which six companies were notified, but a FOIA request filed by Motherboard revealed them to be Microsoft, Nintendo, Sony, HTC, Asus and Hyundai.

“Provisions that tie warranty coverage to the use of particular products or services harm both consumers who pay more for them as well as the small businesses who offer competing products and services,” Thomas B. Pahl, acting director of the FTC’s Bureau of Consumer Protection, said in a release.