On February 10, 2021, the Federal Circuit in Infinity Computer Products, Inc. v. Oki Data Americas, Inc., No. 20-1189 (Fed. Cir. 2021) affirmed a decision by the U.S. District Court of Delaware that patent claims were invalid for indefiniteness based on conflicting positions taken by the patentee during prosecution. Specifically, the Federal Circuit held that the conflicting positions leave one of ordinary skill without reasonable certainty regarding the scope of the invention. This Federal Circuit decision is a reminder to patent applicants that piecemeal success before the Patent Office that does not conform to a coherent overarching prosecution strategy can invalidate patent rights.