President-elect Donald Trump took to Twitter on Wednesday night to personally insult Chuck Jones, the president of United Steelworkers 1999, which represents workers at Carrier’s manufacturing plant in Indianapolis.

The tweet came shortly after Jones appeared on CNN and criticized the recent Carrier jobs “deal” for which Trump took credit.

Trump announced last week that he’d reached a deal with Carrier's parent company, United Technologies, to keep 1,100 of the company’s Indianapolis jobs from leaving the state. Jones was later informed that out of that announced number, only 730 of the jobs would, in fact, remain. According to Jones, he had hoped that Trump would explain this when the president-elect appeared at the facility last week. But when he did not Jones was disappointed and said that Trump “got up there and, for whatever reason, lied his ass off.”

This criticism has apparently led Trump, the next leader of the free world, to publicly bash the union leader. Jones told The Washington Post he learned of Trump’s tweets only after a friend called to tell him he was about to get a lot of attention. “My first thought was, ‘Well, that’s not very nice,’” he said. He later shrugged off the incident and decided to focus on other things—something he said Trump should do as well. “He needs to worry about getting his cabinet filled and leave me the hell alone,” he said.

—Gideon Resnick