Allison Williams was determined to keep wedding private

Girls star Allison Williams reportedly set up a decoy wedding site to fool onlookers in a bid to keep her nuptials "personal and very private".

The actress wed her longtime boyfriend, entrepreneur Ricky Van Veen, at a ranch in Wyoming in September (15), and guests included her Girls co-stars Lena Dunham, Jemima Kirke and Zosia Mamet, and pals Seth Meyers, Katy Perry and John Mayer.

Allison reportedly refused to tell her guests the location of her big day until the last minute and set up a decoy wedding site, and she admits she went to great lengths to keep the ceremony a private affair.

"One of the most special things about the wedding was that it was actually very personal and very private," she tells New York Post gossip column Page Six.

"It was something that mattered to me in a sense of just wanting it to feel really intimate, and to feel like an experience that we shared as a family and with our closest friends. I feel really happy about the fact that it was exactly that... It's an emotional day and people were free to feel whatever emotions they were feeling."

Allison wore a custom-made Oscar de la Renta dress, and she reveals the designer, Peter Copping, embraced her outdoors-style theme.

"Peter (Copping, de la Renta's creative director) grew up being around horses and ranches and immediately understood the aesthetic I was going to be in. It came together kind of organically."

However, the actress admits she did have one big request for her special gown: "I wanted sleeves because I'm always cold."

The couple started dating in 2011 and became engaged in February, 2014, and the wedding was previously postponed after her newsman father, Brian Williams, was suspended by NBC bosses in February (15) for making false statements regarding his coverage of the U.S. invasion of Iraq.