The US Conference of Catholic Bishops has filed a brief urging the Supreme Court to protect women’s sports from participation by biological males who identify as female.

The US Supreme Court is set to hear two cases that could determine if US states may legally reserve girls’ and women’s sports for biological females.

The cases, State of West Virginia v. B.P.J. and Little v. Hecox, will test the constitutionality of laws in West Virginia and Idaho designed to exclude male competitors from female leagues. Both laws have been blocked by federal courts, prompting appeals to the nation’s highest court in the land.