A requirement at Burger King, 99% of whose restaurants are independently owned franchisees, that workers who leave one Burger King cannot go to work at another for at least six months without prior written consent, violates federal antitrust law, a federal appeals court said Wednesday, in overturning a lower court ruling.

Burger King, which is operated by Miami-based Restaurant Brands International, had franchisees sign these “no hire” agreements from at least 2010 until at least September 2018, according to the ruling by the 11th U.S. Circuit Court of Appeals in Atlanta in Jarvis Arrington et al. v. Burger King Worldwide Inc.

At that point, new franchisees were no longer required to sign the agreement, but thousands of those already in business continued to operate under it, the ruling said.

The litigation was filed by former Burger King employees in U.S. District Court in Miami, which dismissed the case. In overturning the lower court, a three-judge appeals court panel cited the 1890 federal Sherman Anti-Trust Act, which forbids contracts that unreasonably restrain interstate or foreign trade.

“Plaintiffs asserted in preventing them from obtaining employment at other Burger King franchise restaurants, the No-Hire Agreement caused them to be paid artificially depressed wages, suffer decreased benefits, and be deprived of job mobility,” the ruling said.

“In Plaintiff’s view, the No-Hire Agreement amounts to an unreasonable restraint on trade,” in violation of the Sherman Act.

The appeals panel agreed. The no-hire agreement “deprive(s) the marketplace of independent centers of decision making (about hiring) and therefore of actual or potential competition,” it said, in quoting the U.S. Supreme Court’s unanimous 2010 ruling in American Needle Inc. v. National Football League, et al, which held that the National Football League Properties’ exclusive contract with Reebok International Ltd. violated the Sherman Act.

The case was remanded for further proceedings.

Attorneys in the case did not respond to requests for comment.