Last week, in McCaster et al. v. Darden Restaurants, Inc. et al., No. 15-3258 (7th Cir. Jan. 5, 2017), the Seventh Circuit relied on Wal-Mart Stores, Inc. v. Dukes, 564 U.S. 338 (2011) and affirmed the district court’s denial of class certification of Plaintiffs’ claims for vacation pay under state law.  The Seventh Circuit’s reliance on Dukes demonstrates that the Supreme Court’s holding extends beyond the discrimination context and applies with equal force in wage and hour class actions (at least within the Seventh Circuit).  The Court concluded that Plaintiffs’ proposed class definition constituted an impermissible “fail safe” class because an individual’s membership in the class turned on the merits of his or her claim, and that Plaintiffs’ alternative class definition did not satisfy the commonality requirement of Rule 23 under Dukes. This decision exemplifies the critical balance plaintiffs must strike in defining their proposed classes; while a “fail safe” class will not be permitted, a class definition that is too broad will not satisfy the requirements of Rule 23.