ATLANTA (AP) — The main athletic association for Georgia high schools voted Wednesday to ban transgender boys and girls from playing on the school sports teams matching their gender identity, saying instead that students must play on teams that match the sex listed on their birth certificates at birth.

The Georgia High School Association’s executive committee, meeting in Thomaston, voted unanimously for the change. It will take effect for the next school year, spokesperson Steve Figueroa said.

Proponents of the ban say transgender girls have an unfair advantage because they were born as stronger males and warn that those born as girls could be denied places on the team or on the podium if playing against transgender girls.