SEATTLE (AP) — Passengers will soon need to wear protective face masks on all Alaska Airlines flights until further notice.

In a statement today, the Seattle-based airline said face masks will be mandatory beginning May 11. And employees who can’t maintain six feet of distance between passengers and other employees will also be required to wear masks.

Alaska says the face mask requirement is one of many safety measures it has taken during the coronavirus pandemic, including more frequent cleaning on flights of places like tray tables and lavatories and blocking middle seats on large aircraft and aisle seats on small planes through May.