The Supreme Court has refused to allow Florida to enforce an immigration law making it a crime for people who are living in the U.S. illegally to enter the state.

The law, enacted this year, made it a crime for unauthorized migrants to enter the state. Challengers say immigration is a federal matter.

Under the law, known as SB 4-C, anyone who “knowingly enters or attempts to enter [Florida] after entering the United States by eluding or avoiding examination or inspection by immigration officers” can be convicted of a first degree misdemeanor.