The Avengers star Cobie Smulders has finally set a wedding date, more than three years after becoming engaged.

Smulders' comedian boyfriend Taran Killam proposed over the Christmas holidays in 2008 and the couple welcomed daughter Shaelyn Cado the following May.

The stars opted to concentrate on their role as parents before becoming husband and wife, with Smulders previously saying, "We're focused on the baby right now, and when we actually have a second (child), then we'll start thinking about that (getting married)."

And even though the actress may not be expecting, she reveals they have finally decided to exchange vows in September and they're eager to make their relationship official.

She tells Us Weekly, "We finally have time to sit down and plan this wedding."

But Smulders admits their three-year-old little girl is the most excited, adding, "She really wants a dress."