An Idaho law restricting which bathrooms transgender students can use in schools will go into effect while a court challenge plays out.

Chief U.S. District Judge David Nye on Thursday denied a request by a plaintiff who is challenging the law to keep it from being enforced until the lawsuit is resolved, The Idaho Statesman reported. In August, Nye had placed the law on hold in August pending his decision.

The law will go into effect 21 days after his ruling.

It prohibits transgender students from using public school restrooms and locker rooms that align with their gender identity. It also allows other students to sue their school if they encounter a student using a bathroom that doesn’t align with their sex assigned at birth.