PHILADELPHIA (JTA) — Sarah Silverman told backers of Bernie Sanders “You’re being ridiculous” after they would not stop chanting his name at the Democratic National Convention.

The comedian, a leading celebrity supporter of Sanders when he was seeking the Democratic presidential nod, endorsed Hillary Clinton to the Democratic national convention here on Monday night.

“I’m with her,” she said to huge cheers. Sanders, who conceded to Clinton earlier this month, is set to speak later in the evening.

Sanders supporters, while a minority in the Wells Fargo stadium, have been vocal on the first day of the convention, issuing scattered boos at Clinton’s name. Lingering resentment over a tough campaign emerged once again over the weekend, after the revelation through a Wikileaks dump that Democratic National Committee staffers had derided Sanders in internal emails.

“I am proud to be part of the Bernie movement and a vital part of that movement is making absolutely sure Hillary Clinton is our next president of the United States,” she said. Sanders and his top surrogates have urged his backers to back Clinton, saying that defeating Donald Trump, the Republican nominee, is imperative.

After Silverman and Sen. Al Franken, D-Minn., finished speaking there was a delay as Paul Simon got ready to perform “Bridge over Troubled Water.”

Sanders supporters started chanting “Bernie!” and Silverman stared into the crowd and said “You’re being ridiculous!”

It shut the shouters up for about minute, something no other speaker had accomplished with such thoroughness. Soon, though, the chants resumed.