Robert Downey Jr. and wife expecting a baby girl

Robert Downey Jr. is going to be a dad again.

The "Iron Man" actor announced Wednesday via social media that he and wife Susan are expecting a baby girl.

On his Facebook page, Downey broke the news to fans by writing, " Um. I don't know if it's a 'man's world', but I'm certain women run it. Susan and I are therefore delighted to announce we are expecting a baby. Girl. November. Rdj."

In a separate post on Twitter, he wondered what the baby girl's zodiac sign will be.

Downey and his producer wife married in 2005, and are already parents to son Exton, 2. The actor also has a 20-year-old son, Indio, from a previous relationship.