Last month, over 18,000 travelers on United Airlines managed to avoid sitting in a middle seat, even when they were feeling hopeless about it.

The airline revealed a new feature in its app back in March that lets passengers choose their seating preferences during booking. If a better seat becomes available, they can be automatically upgraded at no extra cost. Available options include window, aisle, exit rows, or bulkhead seats.

According to United, nearly 40% of passengers who expressed their seating preferences successfully secured their desired seats before taking off.

Passengers will be moved to their chosen seat type, provided it’s in the same service class as their original seat, up to 12 hours before their flight departure.

Many travelers go to great lengths to avoid middle seats, but frequent flyers often have their specific favorite rows or seat types.

Tools like aeroLOPA can assist passengers in determining seat options that offer the best window views, which can be helpful when selecting preferences in United’s app.