We reported earlier this week that four actresses have signed on for a new comedy and the cast has grown once again. Variety is reporting that Party Down star Adam Scott has joined the cast of My Idiot Brother.

The film centers on Paul Rudd's title character, who starts to crash at the homes of his three sisters to try and bring some happiness into their serious lives, but ends up causing chaos along the way. Elizabeth Banks, Zooey Deschanel and Emily Mortimer have signed on to play the sisters and Scott will play the neighbor of Banks' character. Rashida Jones also signed on to the cast earlier this week, playing the girlfriend of Deschanel's bisexual character.

Jesse Peretz is directing the film from a script by Evgenia Peretz and David Schisgall. The film starts shooting next month in New York City.