COLUMBIA, S.C. (AP) — South Carolina’s governor has quietly signed into law a bill that would ban transgender students from playing girls’ or women’s sports in public schools and colleges.

Gov. Henry McMaster’s signature Monday means South Carolina joins about a dozen other states that have passed similar laws requiring transgender students to compete with the gender listed on their birth certificates.

“We have to do everything we can to protect the young men and women in our state who choose to pursue athletic competition, and that’s why I proudly signed this bill into law yesterday,” McMaster tweeted Tuesday. “It’s common sense, boys should play boys sports and girls should play girls sports.”

Opponents of the law say it singles out students who aren’t elite athletes but are just looking for a way to be a regular student.

In Georgia, the main athletic association recently passed a rule that students must play on teams that match the sex listed on their birth certificates at birth.