Freddie Prinze Jr. and Sarah Michelle Gellar
04/09/2009 AT 10:00 PM EDT
Sarah Michelle Gellar and Freddie Prinze Jr. are expecting their first child together, a source close to the couple confirms exclusively to PEOPLE. "They're very excited," says the source, adding that the actress, 31, is due in the fall.
Gellar, who has been married to Prinze, 33, for six years, will next shoot the HBO pilot The Wonderful Maladays, for which she serves as an executive producer. Prinze recently shot the comedy pilot No Heroics for ABC.