Lyft is suing the city of San Francisco, claiming the city unfairly charged the ride-hailing company over $100 million in taxesBloomberg reports. The lawsuit alleges that, over the course of five years, San Francisco unfairly labeled money earned by Lyft drivers as company revenue.

In the complaint, Lyft maintains that its drivers are its customers, not employees. “Accordingly, Lyft recognizes revenue from rideshare as being comprised of fees paid to Lyft by drivers, not charges paid by riders to drivers,” the complaint reads.

The lawsuit is just the latest chapter in a yearslong debate over how gig economy apps should classify drivers. Last summer, Lyft, Uber, and DoorDash notched a win after the California Supreme Court upheld Proposition 22which allows the companies to classify drivers as independent contractors, meaning the companies do not have to provide drivers with full employee benefits.