Apple has been slapped with a lawsuit over a feature built into the software running on its Apple TV set-top box.
A Florida-based movie app maker named CustomPlay has filed suit against Apple, alleging the iPhone maker violates an automatic-rewind patent the company owns, MacRumors is reporting. The lawsuit, which was filed with the U.S. District Court for the Southern District of Florida, hasn’t yet been assigned a judge.
At the center of the lawsuit is a feature called “what did he say?” built into the tvOS operating system inside the Apple TV. When users are watching programming on the Apple TV, they can activate the Siri virtual personal assistant from the device’s remote. They can then say “what did he say?” or a variation of the question and the Apple TV’s software will rewind the programming several seconds and play it again. In a 2015 press event, Apple (AAPL) CEO Tim Cook touted the feature as a helpful way of using Siri.
Get Data Sheet, Fortune’s technology newsletter
However, the folks at CustomPlay argue that they invented the feature in 1998 and were awarded a patent in 2002. That patent, which was cited in the lawsuit, describes a technology for replaying a video using either voice commands or a button a remote control. According to a listing on the U.S. Patent and Trademark Office (USPTO), the patent, called “Replaying with supplementary information a segment of a video,” is still valid.
In the lawsuit, CustomPlay said that Apple should be aware of the patent and is liable for damages, according to MacRumors. The company didn’t specify how much in damages it’s seeking from the lawsuit.
Apple did not immediately respond to a Fortune request for comment on the suit.