Much attention has been paid in recent years to legal issues arising from standard setting, assertion of standard-essential patents, and the requirements imposed by standard-setting organizations that standard-essential patents be licensed on reasonable terms. This Feature argues that a fundamental aspect of the antitrust laws, heretofore overlooked in this context, can play an important role in ensuring that the rules established by standard-setting organizations are effective in preventing owners of standard-essential patents from engaging in patent holdup. It has long been a basic principle of antitrust law that when firms collaborate to engage in conduct that has efficiency benefits, like standard-setting, they violate the antitrust laws if their collaboration also harms competition more than necessary to obtain the efficiency benefits. Both standard-setting organizations and their members can violate Section 1 of the Sherman Act if the organization’s rules are ineffective in preventing owners of standard-essential patents from exploiting the monopoly power they gain as a result of the standard.