The U.S. Supreme Court on Tuesday sided with Samsung in its big-money smartphone patent fight with Apple, throwing out an appeals court ruling that the South Korean company had to pay a $399 million penalty to its American rival for copying key iPhone designs.

The 8-0 ruling, written by Justice Sonia Sotomayor, held that a patent violator does not always have to fork over its entire profits from the sales of products using stolen designs, if the designs covered only certain components and not the whole thing.

The justices sent the case back to the U.S. Court of Appeals for the Federal Circuit in Washington to determine how much Samsung must pay. But they did not provide a road map to juries and lower courts on how to navigate similar disputes in the future.