Can a U.S. patent be invalidated due to an inaccurate translation of the non-English priority patent application? The answer is most definitely “Yes.” This article examines the recent Federal Circuit decision in which this occurred, IBSA Institut Biochimique, S.A. v. Teva Pharm. USA, Inc., 966 F.3d 1374 (Fed. Cir. 2020), and discusses the procedural framework on how to prevent and correct such a problem.