As of May 28, Southwest Airlines’ new charger policy is in effect. The change comes after multiple safety incidents and dozens of recalls involving overheating or exploding chargers, according to Travel and Leisure.

Southwest Airlines passengers must soon keep portable chargers visible during flights due to rising lithium battery fire incidents. The policy begins May 28.

Portable chargers and power banks might be useful additions to your carry-on luggage, but they’re also a potential fire risk. Now Southwest Airlines is tightening rules around their use on board aircraft.