Christopher Guest has joined the cast of the upcoming Night at the Museum sequel, Night at the Museum: Battle of the Smithsonian.

Christopher Guest (Spinal Tap, Waiting for Guffman… among other great roles) will take on the part of Ivan the Terrible.

Night at the Museum - starring Ben Stiller, Robin Williams, Ricky Gervais and Owen Wilson - will also include Jon Bernthal (Al Capone), Bill Hader (Gen. George Armstrong Custer) and French actor Alain Chabat (Napoleon).