Bags will no longer fly free on Southwest Airlines.

The carrier announced Tuesday that it will begin charging certain passengers to check their first two bags on flights, a significant shift at the company long prized by customers for the perks that set it apart from other major U.S. airlines.

The new rules will take effect on flights booked on or after May 28. Southwest did not specify how much it will charge for checked bags.

The new fee is part of a series of changes announced by the company that it says will reward its most loyal customers and help it “return to the levels of profitability that both we and our Shareholders expect,” president and CEO Bob Jordan said in a statement.

It’s the latest departure of a long-standing Southwest tradition. Last summer, the Dallas-based carrier announced it would also end its open seating policy on flights and replace it with an “assigned and premium seating” process.

Southwest has had a financially turbulent few years. Just over a year ago it was hit with a $140 million fine for a major meltdown that stranded millions of travelers during the 2022 holiday season, and last month the company laid off around 1,750 employees, or roughly 15% of its corporate workforce. Southwest has been facing growing pressure from the activist investment firm Elliott Investment Management, which acquired at least a 10% stake in the company and has been pushing for changes at the airline.

But the newly announced checked bag fee represents a major about-face for one of the largest carriers in the U.S. Last September, Jordan said at a company event that Southwest was “passionate” about its “customer-friendly policies” such as allowing passengers to check two bags for free, The Points Guy reported.

Southwest’s new checked bag fee policy has several exceptions. Preferred members of its loyalty program and customers who buy “Business Select” fares can check two bags for free, while other members of its loyalty program can check one bag at no charge. The company said it will also credit one checked bag for customers who have its loyalty program credit card.

Southwest also announced Tuesday that it will recalculate how it awards points through its loyalty program, giving more points to fliers with pricier fares and fewer points to passengers with cheaper fares. The carrier will also introduce a new “Basic” fare for its lowest-priced tickets.