Affleck, who won an Oscar for writing 1997 movie Good Will Hunting with Damon, gave his pal plenty of tips while he was working on Promised Land with John Krasinski.
Damon and Krasinski both star in the film and wrote the script together, and The Office star admits he was grateful to have help from Argo director Affleck.
He tells New York Post gossip column Page Six, ""He read the script, pretty much every other draft along the entire way. We were really lucky to have his advice and his blessing because he really loved the movie.""
Promised Land, directed by Gus Van Sant, highlights the controversial gas extraction technique known as fracking and tells the story of two salesmen who attempt to buy drilling rights from residents of a small town.