This Airline Is About to Shrink the Size of Carry-on Bags Allowed on Board

In a few months, Alaska Airlines passengers may have to downsize. The airline is decreasing the maximum dimensions allowed for carry-on baggage.

Beginning June 4, passengers’ carry-on items must measure 22 x 14 x 9 inches (including wheels and handles). The change is a significant decrease from current measurements of 24 x 17 x 10 inches.

Alaska explained that its current size allotment is “larger than most other international and domestic airlines allow” and that the change was made to “make sure that your carry-on bag will be accepted aboard all the flights within your itinerary.”

Related: Shop the Perfect Sized Carry-on for Your Airline

The airline’s reasoning is logical. Over the past few years, several other airlines have shrunk the maximum size of carry-ons allowed in the overhead compartment. In 2015, the International Air Transport Association issued guidelines that set the ideal carry-on size at 21.5 x 13.5 x 7.5 inches. Most major U.S. airlines followed these guidelines. Onboard American, Delta, JetBlue, and United, the maximum size for a carry-on is now 22 x 14 x 9 inches.

Southwest is the only airline that allows its passengers a slightly larger carry-on: 24 x 16 x 10 inches.

In its explainer, Alaska also notes that stricter carry-on dimensions will allow more passengers to store their luggage in the overhead compartments (as opposed to a gate-side check). Overhead space is an industry-wide concern.

The other method for dealing with limited overhead compartment space — implemented by American and United — is basic economy, which charges passengers for use of the overhead compartment.