On June 22, 2015, the U.S. Supreme Court issued a decision that rejected calls to overturn its 1964 decision in Brulotte v. Thys Co., which established rules governing enforcement of contracts entered into between patent holders and licensees. The Kimble decision was a victory for WLF, which filed a brief in the case arguing that parties have been relying on the Brulotte rule for more than 50 years when drawing up patent license agreements and that a decision overturning Brulotte would unnecessarily upset their settled expectations. Brulotte established a bright-line rule regarding patent license agreements: they are unenforceable to the extent that they require royalty payments for use of the patent after the patent has expired. The Court agreed with WLF that stare decisis—the principle that counsels courts to stand by their prior decisions—dictates that any change in the Brulotte rule should come from Congress (which is free to amend the patent laws), not the courts.