SEATTLE (AP) — A divided Washington Supreme Court ruled Thursday that the state’s dairy workers are entitled to overtime pay if they work more than 40 hours a week.

The 5-4 ruling Thursday extends overtime protections for the first time into Washington’s agriculture sector. For the past 60 years state law has exempted farmworkers from classes of workers who are entitled to overtime, but the court found that unconstitutional as applied in the dairy industry.

Dairies say it will mean vastly increased labor costs and could prompt more to turn to robotics.

The ruling came in a 2016 lawsuit brought on behalf of 300 workers against DeRuyter Brothers Dairy in Outlook, southeast of Yakima.

The state Supreme Court has recently been expanding labor protections for agricultural workers, including a ruling entitling them to paid rest breaks.