'Mad Men' Star Jessica Pare Is Pregnant

Jessica Paré is expecting her first child with boyfriend John Kastner.

— -- "Mad Men" is winding down, and Jessica Paré is already prepping for her next big role: Mom.

The actress is expecting her first child with her boyfriend John Kastner, her rep confirmed to ABC News.

Paré, 33, has been dating her musician beau since 2012, according to People. Last month, Kastner made the pregnancy announcement on his Instagram feed a few weeks ago.

In the photo, shown below, his young daughter, Summer Lee, can be seen wearing a T-shirt with a telling message: "I'm going to be a big sister!"

Neither Paré nor Kastner have confirmed the baby's due date.