The United Auto Workers union will represent 3,000 hourly workers at two DaimlerChrysler AG Freightliner LLC plants in North Carolina.

The UAW won the right through card-check votes at the Cleveland and Gastonia plants. A majority of workers signed cards in favor of joining the union in January, reports Reuters.

The UAW has had a contentious relationship with Freightliner, as it has seven major manufacturing plants in the U.S. employing 13,000 workers. Only its plant in Mt. Holly, NC, is unionized. The UAW or another trade union will now represent workers at four of the seven facilities.

There’s no word on when contract negotiations will begin, but Freightliner says it will “bargain in good faith” with the union.