An incident in which a passenger got stuck in a plane bathroom mid-flight and pilots were forced to make an emergency landing has prompted the FAA to propose a regulation that could affect more than 2,600 Boeing 737 airplanes in the US.

In its rule change proposal posted Friday, the FAA said that being stuck in an airplane bathroom could result in serious injury to passengers in the event of an otherwise survivable emergency event. The agency recommended that the latches be replaced with ones with an improved design. Several 737 models would be affected by the change and the FAA estimates a cost of up to $1,300 per airplane, for a total cost of $3.4 million to US airlines and other operators.

Boeing has had a better start to 2025, delivering 56% more jets in the first quarter than it did last year and closing its gap with European rival Airbus.