NORFOLK, Va. — The U.S. Navy has changed its policy to allow all sailors working on aircraft carriers to get eight hours of uninterrupted sleep.

The Virginian-Pilot reported Thursday that the change is a reaction to two fatal ship collisions that killed 17 crew members in the Pacific Ocean last year. The Navy found that fatigue and poor sleep management contributed to the collisions.

The USS John S. McCain and an oil tanker collided near Singapore in August 2017, killing 10 sailors. The USS Fitzgerald and a container ship collided off Japan in June 2017, killing seven sailors.

Both of the Navy ships were guided missile destroyers.

The policy change was made in August. It was first reported by the Navy Times.