Zach Galifianakis is to marry his longtime partner Quinn Lundberg.

The 42-year-old Hangover star will marry the 29-year-old on 11 August, according to a website that obtained a copy of the wedding invite.

A source told Celebuzz: "While it has the formal and standard details of who, what, when, where - including Zach's full name Zachary Knight Galifianakis and his fiancée's, Mary Quinn Lundberg - it is also very funny.

"Zach included a drawing of himself and his bride-to-be. He made sure he looked like a little troll, while Quinn is a stunning tall blonde princess."

It is unclear whether Galifianakis ever got engaged to Lundberg, who is vice president and co-founder of Growing Voices, a charity dedicated to giving back to the community.

The comedic actor next appears with Will Ferrell and Jason Sudeikis in The Campaign, and The Hangover franchise will continue next year with its third installment, also starring Bradley Cooper and Ed Helms.

The Hangover III will be filmed in Las Vegas.

While the second installment in the comedy franchise was set in Asia, the third and final movie will return to its roots in the gambling capital in the state of Nevada.