Southwest Airlines, known for free bags and open seating, is overhauling policies, leaving loyalists questioning if it’s still the airline they loved.

The carrier announced Tuesday that it will begin charging certain passengers to check their luggage on flights, a significant shift at the company long prized by consumers for its perks.

Southwest Airlines will start charging passengers to check bags for the first time. It’s a stunning reversal that shows the low-cost pioneer is willing to part with a customer perk executives have said set it apart from rivals in more than half a century of flying in hopes of increasing revenue.