The U.S. Supreme Court sided on Thursday with Starbucks in the coffee chain’s challenge to a judicial order to rehire seven Memphis employees fired as they sought to unionize in a ruling that could make it harder for courts to quickly halt labor practices contested as unfair under federal law.

The justices threw out a lower court’s approval of an injunction sought by the U.S. National Labor Relations Board (NLRB) ordering Starbucks to reinstate the workers while the agency’s in-house administrative case against the Seattle-based company proceeds.