Companies that require employees to go through security screenings at the end of their workday are not required to pay overtime, the U.S. Supreme Court ruled on Tuesday.

The unanimous ruling in Integrity Staffing Solutions v. Busk was a big win for business groups that told the court in amicus briefs that security checks are used by nearly two-thirds of retailers to curb employee theft. The National Retail Federation warned the justices that the outcome of the case was “critically important.”

“The court's unanimous decision reinforces the clear dividing line between compensable work and noncompensable pre- and post-shift activities that had been widely understood by employers for many years,” said Proskauer Rose partner Edward Brill, who wrote a brief in the case for the Retail Litigation Center, the Chamber of Commerce and others.