Get next year's Oscar ballots ready.

Ewan McGregor is joining Meryl Streep, Julia Roberts and a large ensemble cast in "August: Osage County" from The Weinstein Company. 

The film is an adaptation of Tracy Letts’ Tony-winning play which also won a Pulitzer in 2008.

"August" centers on The Westons, an Oklahoma family with Streep as the overbearing matriarch, who must ut their differences aside after the father goes missing. 

According to Deadline, McGregor is set to play a college professor named Bill Fordham who leaves his wife Barbara Weston (Roberts) for one of his students. 

The name cast also includes Benedict Cumberbatch, Dermot Mulroney, Chris Cooper, Sam Shepard and Abigail Breslin. John Wells ("The Company Men") is directing from a script by Letts.

McGregor was recently seen in Steven Soderbergh's "Haywire" and in "Salmon Fishing in the Yemen." He'll next appear alongside Naomi Watts in "The Impossible" and in next year's "Jack the Giant Killer."

"August" starts production on September 24.