Armstrong Teasdale has defeated a former equity partner’s age bias lawsuit challenging the firm’s mandatory retirement age, with a Missouri federal judge ruling that the partner couldn’t claim to be an “employee” under a federal anti-discrimination law because he had already made a similar argument in state court and lost.

U.S. District Judge Henry Edward Autrey in St. Louis, who last year denied Armstrong Teasdale’s early attempt to dismiss former partner Joseph von Kaenel’s age bias suit, has now determined that the law firm deserves a judgment on the pleadings. The decision comes in a suit alleging von Kaenel was unfairly pushed out in 2014 under a mandate that partners retire from Armstrong Teasdale at the end of the calendar year in which they turn 70.