Late-night host Conan O’Brien says it is a mistake for comedians to go after Donald Trump too hard. The 62-year-old talk show host had an hour-long interview with Oxford Union where he delved into what he sees as comedic pitfalls, particularly during this era in American politics, and one of them is being too aggressive when going after the president. This is despite other late-night hosts like Jimmy Kimmel focusing on Trump as their comedic target.

“Comedy needs a straight line to go off of,” O’Brien explained in his sit-down interview with the debating society in Oxford. “And we don’t have a straight line right now. We have a very bendy, rubbery line. We have a slinky.”

The comedian said it has been difficult to lampoon Trump since the president’s actions are like “a fire hose that’s whipping around spewing water at 100 miles an hour.”

However, he says that it’s a trap to go after Trump too aggressively. “I think some comics go the route of I’m going to just say ‘F Trump’ every all the time or that’s their comedy. And I think, well now a little bit you’re being co-opted because you’re so angry. You’ve been lulled. It’s like a siren leading you into the rocks.”

O’Brien continued, “You’ve been lulled into just saying F Trump, F Trump, F Trump. Screw this guy! … And I think you’ve now just put down your best weapon, which is being funny, and you’ve exchanged it for anger.”

While he admits that some comedians would respond to his criticism by saying that “things are too serious now,” he believes they need to channel that anger into finding a better joke, since “good art will always be a great weapon, will always be a perfect weapon against power.”

“If you’re just screaming and you’re just angry, you’ve lost your best tool in the toolbox,” O’Brien concluded.

The comedian admitted in an interview last year that the traditional late-night format is fading, though he believes that Stephen Colbert will still make an impact on the entertainment industry. He was also a producer, alongside Jodie Foster, for the Netflix mystery thriller The Beast In Me.