A contract between shipping companies and 22,000 West Coast dockworkers has expired.

But both sides continue to talk and said they want to avoid a strike that could savage an economy already stressed by soaring inflation and supply chain troubles. The contract that expired last Friday covered workers at ports from California to Washington state that handle nearly 40% of U.S. imports.

Both sides say they will keep cargo moving until an agreement is reached. A 2002 lockout and a 2015 strike cost the U.S. economy billions of dollars.

“While there will be no contract extension, cargo will keep moving, and normal operations will continue at the ports until an agreement can be reached,” said a joint statement from the Pacific Maritime Association and the International Longshore and Warehouse Union.