Kentucky man put glass in fast-food cups. He’ll likely be eating prison food soon.

A Kentucky man who worked at a cup-manufacturing plant has pleaded guilty to putting glass shards in cups sold to fast-food restaurants.

Waylon J. Horton, 44, faces up to 10 years in prison when he is sentenced.

Horton admitted putting broken glass into cups at the Dart Container plant in Hart County two times in July 2016, according to court records.

People found glass in cups from the factory at unnamed restaurants in Kentucky, Ohio and Indiana.

After Dart learned of the problem, it put distribution on hold for a time. A search turned up seven more boxes with cups that had broken glass in them, according to a news release from U.S. Attorney Russell M. Coleman.

Police found glass shards in a tool belt Horton used at the factory, an officer said in a court document.

Before the tampering incidents, Horton had gotten upset with the company because he was told he would have to begin working a longer shift, prosecutors said in a court motion.

Horton pleaded guilty Friday in federal court in Bowling Green. He is to be sentenced in October.