The U.S. Navy awarded BAE Systems San Diego Ship Repair a contract modification worth almost $50 million, covering maintenance work on the amphibious ship USS Comstock.

Work will include depot-level maintenance, alterations and modifications to update and improve the ship’s military and technical capabilities.

The deal is worth $49.8 million. Optional work would increase the sum to $50 million. The Navy is calling for work to be finished by October 2018.

The Comstock is a 609-foot Whidbey Island-class dock landing ship commissioned in 1990. It is able to carry up to 500 U.S. Marines in addition to its crew of 413. Four hovercrafts can go in its well deck.

The Southwest Regional Maintenance Center of San Diego awarded the deal.