Minka Kelly shared a photo with her friends for Mandy Moore's (far right) wedding anniversary. Credit: Courtesy of Minka Kelly

They may have been dressed for the '50s, but Minka Kelly's Instagram picture with her pals wasn't a flashback photo. The Almost Human star, 33, happily dressed up for the theme anniversary party at the American Legion Post for her pal Mandy Moore and her hubby Ryan Adams

"The girlzzzz Happiest Anniversary @mandymooremm & Ryan!!!" Kelly captioned a photo of the five of her friends, including Moore, 29, decked out in partywear. 

A source who attended the party told Us Weekly, "Everyone was told to wear their best '50s prom outfits. People were toasting Ryan and Mandy. They were lovely together. Slim Jim Phantom performed all night and was playing hillbilly rock tunes."

Moore and indie rocker Adams, 39, got married on March 10, 2009 after almost a year-long engagement. In 2012 the Tangled star told Us Weekly she wasn't ready for having kids just yet. 

"We're enjoying the animal children first," Moore reasoned of the couple's pets -- rescue cats Vincent and Theo and adopted dog Joni.