An Arizona federal judge ruled late last week that certain drivers for Phoenix-based Swift Transportation are employees, not contractors. The ruling is a setback for Swift and follows a seven-year legal battle.

The suit named five drivers but could open up the company to similar claims for back wages from thousands of truckers.

Swift is the largest truckload motor carrier in North America with more than 45 terminals in the U.S. and Mexico. The Wall Street Journal reports that the case is similar to lawsuits brought by drivers for Uber, FedEx, Amazon and other companies that operate large vehicle fleets.