Federal law gives airlines and their employees broad immunity from civil lawsuits when they alert transportation authorities to potential threats, the U.S. Supreme Court ruled on Monday as it reversed a $1.4 million defamation verdict against an airline that reported a pilot was “mentally unstable.”

“Congress meant to give air carriers the ‘breathing space’ to report potential threats to security officials without fear of civil liability for a few inaptly chosen words,” Justice Sonia Sotomayor wrote in Air Wisconsin Airlines Corp. v. Hoeper.