Fans of comic Gad Elmaleh, who has been dubbed the Jerry Seinfeld of France, got a big surprise from the real Jerry Seinfeld on Thursday night.

Spies tell us Seinfeld did a 10-minute warm-up before Elmaleh’s set at Joe’s Pub at The Public, and it was so unexpected that audience members first thought the whole thing was a joke.

“Harrison Greenbaum was the first comic. When he announced that Jerry was the next comic, the crowd didn’t react that strongly, I think because they figured he was kidding,” a spy tells us.

But when Seinfeld walked out, fans were clearly shocked and excited.

Elmaleh, who voiced Seinfeld’s character in the French version of 2007’s “Bee Movie,” is set to open for Seinfeld at the Beacon Theatre on June 8. The Moroccan-French comedian is performing at Joe’s Pub through June.