Kimmel had a particularly hard time getting out “tuberculosis,” prompting the late night host to declare: “It was a hard night. It was a hard night. I’m not even going to attempt that again.”

The comedian was calling back to his monologue’s opener, where he expressed his disappointment over sidekick Guillermo Rodriguez being eliminated on “Dancing With the Stars.”

Kimmel was able to get his monologue back on track, however, mocking Trump for calling himself a “freaking genius” for passing cognitive tests.

“But if anyone was worried about his brain, don’t,” Kimmel said. “He’s good. He’s giving himself cognitive tests and he’s passing them with flying colors.”

After playing footage of Trump’s rally speech, in which he rattled of the words he was supposedly given during a cognitive test, Kimmel quipped: “Sir, you aced this test you just made up. This is the test you would give your grandfather after he fell off a stepladder.”

On Trump’s declaration that he’s a “genius” for passing multiple cognitive tests, Kimmel added, “If you believe that, then you will also believe I’m sending you $5,000 a piece.”

Watch Kimmel’s full monologue above. A representative for the White House did not immediately respond to TheWrap’s request for comment.

“Jimmy Kimmel Live!” airs weeknights at 11:35 p.m. ET on ABC.