Ford has fired back at GM in the fight over the names of their advanced driver assistance systems. The Blue Oval is asking the U.S. Patent Office to rescind GM’s trademarks on the terms “Cruise” and “Super Cruise.”

The fight started back in April when Ford released “BlueCruise,” its competitor to GM’s hands-free driver aid “Super Cruise.” General Motors claimed it asked Ford to change the name of its system to avoid confusion but took legal action in July when the company refused to change its system’s name.

“GM’s Super Cruise hands-free driver assistance technology was announced in 2012 and has been used commercially in-market since 2017. Our majority-owned self-driving subsidiary Cruise has been in business since 2013,” said GM in a filing. “While GM had hoped to resolve the trademark infringement matter with Ford amicably, we were left with no choice but to vigorously defend our brands and protect the equity our products and technology have earned over several years in the market.”

Read More: GM Taking Legal Action Against Ford Over BlueCruise Hands-Free Driving System

Last week, though, Ford reiterated its position that the suit was frivolous, taking this action to defend itself from GM’s suit, per Reuters.

“To defend itself, Ford has no choice but to ask the U.S. Patent and Trademark Office to rescind both of GM’s “Cruise” and “Super Cruise” trademark registrations that should have never been registered in the first place,” said Ford. “Any number of companies use the word ‘cruise’ in connection with driver assist technology.”

Indeed, the company cited examples such as Mack Trucks’ “Predictive Cruise,” Hyundai’s “Smart Cruise Control,” and “Autocruise,” which is used by automotive supplier ZF Friedrichshafen AG.