Southwest Airlines is switching over to their new reservations system on Tuesday, May 9 known as One Res and to celebrate, they will be offering all customers a free drink if flying tomorrow to kick off this new milestone for the airline.

Customers shouldn’t see much of a difference in the booking process, as the changes are more on the back-end including the ability to better forecast flights, which is one of the reasons Southwest will no longer oversell flights, and allows the ability to add red-eye flights in the future. The new reservations system will accept foreign currency as well.

Confirmed by a Southwest Flight Attendant: As a Gesture of Goodwill, all Customers (21+) may receive one complimentary premium beverage on May 9. If Customers (21+) request an alcoholic drink on Tuesday, May 9, feel free to simply tell them “This drink is on me! It’s in celebration of our next generation reservation system and to thank you for being a loyal Customer.”

Can’t decide what to order, here’s a look at the cocktails that Southwest is serving up at 35,000 feet. In addition, they offer a selection of beer and wine, all normally which are $5, will be complimentary.

Are you flying Southwest Airlines tomorrow? Which drink will you choose?