Jimmy Fallon is going to jump in the lake.
The new "Tonight Show" host confirmed via Twitter on Monday morning that he'd join Chicago Mayor Rahm Emanuel in Sunday's Polar Plunge -- the annual dip into Lake Michigan that benefits the Special Olympics.
And in true comedic style, he even offered a catchy hashtag: #SwimmyFallon.
The tweet seems to put an end to the nearly week-long banter the two men have had on social media.
It all started with a remark Fallon made even before the debut of his incarnation of the NBC program.
"All he has to do is make a phone call," Fallon said. "He can host if he wants to. I'm scared of that guy."
When Emanuel caught wind of it, he took to social media and accepted the invite with one condition: Fallon had to join in Sunday's Polar Plunge.
As these things go, social media latched onto the idea with the #JimmyPlungeWithUs hashtag.
Emanuel agreed to take part in the Chicago Polar Plunge after challenging the city's school children to read two million books last summer.
There was no immediate word as to when Emanuel would appear on "The Tonight Show."