A U.S. appeals court on Monday said a California federal judge must reconsider her ruling that Grubhub Inc was correct to treat a delivery driver as an independent contractor rather than an employee, in light of a major shift in state law governing worker classification.

A unanimous three-judge panel of the 9th U.S. Circuit Court of Appeals said that because a strict classification standard adopted by the California Supreme Court in 2018 was retroactive, the federal judge must apply it in a case brought by former Grubhub driver Raef Lawson.