American Airlines pilots union has rejected the company’s offer of as much as double pay for working trips around the holidays, a measure aimed at avoiding a repeat of recent mass flight cancellations.

The Allied Pilots Association’s board of directors voted against the premium pay of at least 150% and double pay for picking up open holiday trips. The union said late Tuesday that it wants more permanent changes to how the airline builds its schedule. The labor union is in the middle of contract negotiations with the airline.

Some airlines have struggled to balance the return of travel demand and understaffing. American canceled more than 2,000 flights in late October and early November after bad weather and a cascade of staffing shortages. Southwest Airlines and Spirit Airlines have faced similar issues that have cost them $75 million and $50 million, respectively.