States can’t cut religious schools out of programs that send public money to private education, a divided Supreme Court ruled Tuesday.

By a 5-4 vote with the conservatives in the majority, the justices upheld a  Montana scholarship program that allows state tax credits for private schooling in which almost all the recipients attend religious schools.

The Montana Supreme Court had struck down the K-12 private education scholarship program that was created by the Legislature in 2015 to make donors eligible for up to $150 in state tax credits. The state court had ruled that the tax credit violated the Montana constitution’s ban on state aid to religious schools.

Chief Justice John Roberts wrote the opinion that said the state ruling itself ran afoul of the religious freedom, embodied in the U.S. Constitution, of parents who want the scholarships to help pay for their children’s private education. “A state need not subsidize private education. But once a state decides to do so, it cannot disqualify some private schools solely because they are religious,” Roberts wrote.

In a dissent, Justice Sonia Sotomayor described the ruling as “perverse.”

“Without any need or power to do so, the Court appears to require a State to reinstate a tax-credit program that the Constitution did not demand in the first place,” she said.

Parents whose children attend religious schools sued to preserve the program. The high court decision upholds families’ rights “to exercise our religion as we see fit,” said Kendra Espinoza, the lead plaintiff in the lawsuit whose two daughters attend the Stillwater Christian School in Kalispell, Montana, near Glacier National Park.