The Pentagon announced that General Dynamics Nassco is in line to receive a $20.7 million U.S. Navy ship repair contract.

The deal is a modification to a previously awarded contract to conduct maintenance, alterations and modifications to the San Diego-based amphibious assault ship USS Boxer. Work is expected to be complete by December 2015.

The Southwest Regional Maintenance Center in San Diego awarded the contract.

General Dynamics (NYSE: GD) reported $31.2 billion in revenue in 2013, down slightly from $31.5 billion the previous year. Its Marine Systems business encompasses other shipyards building submarines and destroyers. The Marine Systems business reported $178 million worth of income in Navy ship engineering, repair and other services during 2013.