Want to board first on a Southwest Airlines flight? Now you can pay $40 for the privilege.

Southwest Airlines will let people pay to be part of their first boarding group, group “A.” The airline does not have assigned seating and lets passengers board in three groups, A, B and C.

Currently, passengers can ensure they board first by buying a special business class ticket or joining a loyalty program. Now, everyone will have that option if spots are available. Passengers will be able to pay at the gate starting 45 minutes before a flight leaves.

Facing higher fuel and other costs, airlines have sought to boost revenue in a variety of ways including charging extra to check a bag or sit next to a loved one.