President Biden’s public expressions of frustration tend to be mild, such as his penchant for saying “c’mon, man,” but according to a report Monday in Axios, in private “Biden has such a quick-trigger tempter that some aides try to avoid meeting alone with him,” the report says. “Some take a colleague, almost as a shield against a solo blast.”

The report cites unnamed “current and former Biden aides” who say the boss often erupts in profanity-laced tirades (“God dammit, how the f**k don’t you know this?”) aimed at both senior and lower-level aides. “No one is safe,” one official told Axios. The White House declined to comment on the report.

It’s not the first time Biden’s temper has made news. Last year, NBC News reported that the president “lost his temper” and raised his voice during a call with Ukrainian President Volodymyr Zelenskyy. Biden had just finished telling Zelenskyy he’d approved another $1 billion in U.S. military assistance for Ukraine’s war with Russia when Zelenskyy “started listing all the additional help he needed and wasn’t getting.” Angry, the president told Zelenskyy he could show more gratitude.

The president’s amiable relationship with journalists has occasionally led to tense moments, such as an exchange in June between Biden and a reporter from the New York Post, who asked about the president’s son. Biden at first laughs off the question, but when the reporter followed up, Biden snapped at him and raised his voice:

Axios quotes Biden aides who believe “the president would be better off occasionally displaying his temper in public as a way to assuage voter concerns that the 80-year-old president is too disengaged and too old for the office.”