Sissy Spacek and Mary Steenburgen are joining Reese Witherspoon and Vince Vaughn in Four Christmases for New Line, according to The Hollywood Reporter.
Kristin Chenoweth and Robert Duvall also star in the Spyglass Entertainment holiday-themed romantic comedy from director Seth Gordon and writers Jon Lucas and Scott Moore.
The story revolves around a newly married couple (Witherspoon and Vaughn) who decide to brave visits to all sets of their parents for the Christmas holiday -- despite the scars each has from being raised in broken homes.
Spacek will play the slightly spacey, New Age mother of Brad (Vaughn). Steenburgen will play the chameleon-like mother of Kate (Witherspoon), whose personality changes depending on whom she's married to or dating. Chenoweth plays Kate's controlling, type-A sister and Duvall plays Brad's gruff father.
The film is slated for release during the 2008 holiday season.