The Postal Service initially scheduled Groff off on Sundays until July 2018, after which time he began facing disciplinary action for missing Sunday shifts. In a rare unanimous decision, the court said a 1977 Supreme Court ruling saying that businesses can reject an accommodation if it caused an undue hardship did not apply here.

A district court and appeals court had ruled in favor of the Postal Service. In an opinion written by Justice Samuel Alito, the court ruled that in the future courts “should resolve whether a hardship would be substantial in the context of an employer’s business in the commonsense manner that it would use in applying any such test.”

While the decision clarified the 1977 ruling, styled Trans World Airlines v. Hardison, it did not strike it down as many religious supporters had hoped. The case now returns to the lower court for further litigation.

Still, John Bursch, senior counsel for the Alliance Defending Freedom, praised the Supreme Court’s decision as one where they believe religious liberty was restored.

“Federal law protects employees’ ability to live and work according to their religious beliefs,” Bursch said. “Employers must provide reasonable accommodations for employees’ religious practice unless doing so imposes undue hardships on their operations. For too long, that duty had been erased by a misguided court ruling.”