Costco has reached a tentative deal with the Teamsters union representing 18,000 of its workers across six states, averting a potential strike just hours after the previous collective bargaining agreement had expired.

The Teamsters had initially signaled that they intended to strike the moment the old agreement ran out at 11:59 p.m. on January 31. But the new deal was announced by the union hours after that deadline on February 1, CNN reports, although the terms of the tentative contract won't be disclosed until it's ratified by rank-and-file members of the union.

The Teamsters make up roughly 8% of Costco's 219,000 U.S. employees, spread out across 56 stores in Maryland, New Jersey, New York, Virginia, California and Washington state. The union has been pushing for higher wages, as well as improvements to paid leave, bereavement policies, sick time, and seniority pay structures. If they had gone on strike, it would have been the largest work stoppage at a U.S. retail chain in history, and the first for a big-box retailer.

On January 31, Costco announced that it would be raising the pay for all of its current employees at non-union stores to $30.20 an hour, with additional one dollar an hour increases planned for each of the next two years. Starting pay for newly-hired employees moving forward was raised by 50 cents to $20 an hour as well.