Robert De Niro had Monday night’s “Jimmy Kimmel Live” audience howling with his blunt description of Donald Trump.

Host Jimmy Kimmel asked the iconic actor about something they have in common ― “We have both been immortalized on social media by our former President Donald Trump.”

Kimmel pointed to social media screeds from Trump directed at De Niro, including one from December last year, which read in part: “Robert De Niro, whose acting talents have greatly diminished, with his reputation now shot, must even use a teleprompter for his foul and disgusting language, so disrespectful to our Country.”

“Is that true?” Kimmel asked. “Do you have to use a teleprompter when speaking about President Trump, or are you able to just kinda riff on your thoughts on him?”

De Niro, smiling, replied: “He’s so fucking stupid.”

Kimmel burst into laughter, and the audience erupted in hoots and applause.

When it finally died down, De Niro went on, “I mean, look at the lame, inane things that he says. He’s so stupid he can’t even say anything clever. He’s a fucking moron.”

“But he’s a scary one,” he added, “and in all seriousness, and we know it here, people have to get out and vote and vote and vote and vote.”

Kimmel has been the subject of Trump’s ire much more recently. On Sunday night, the comedian read aloud Trump’s critique of his Oscars hosting performance right from the awards ceremony stage, retorting, “Isn’t it past your jail time?”

Watch the interview below.