Fina, the global governing body for swimming, said Sunday it would ban transgender women from participating in women’s swimming events if they transitioned after the age of 12. Instead, those who have transitioned will be able to compete in an “open” category for those who do not identify with their gender at birth. The decision, which 71 percent of Fina’s members voted for, was made to enforce “competitive fairness,” its executive director said in a statement. But the move—decided during Pride Month—came as trans athletes face a barrage of difficulties in sports across the world. Swimmer Lia Thomas has become a hallmark case for trans swimmers, winning championships even as conservative media—and some of her own college teammates—have spun off her success as unfair.