Acting in a case at the intersection of patent and antitrust law, the Supreme Court on Wednesday issued a ruling that makes it harder for upstart companies and generic manufacturers to challenge patent holders’ power in the marketplace.

The 8-0 decision, written by Justice John Paul Stevens, overturns a 1947 decision that was issued when Stevens was a law clerk for the late Justice Wiley Rutledge. Rutledge voted in the majority.