Paris Hilton Nicole Richie
Credit: Jeff Vespa/Getty Images, Jim Spellman/WireImage

It's official: we are missing The Simple Life. On Monday, Nicole Richie celebrated her 34th birthday, and her old friend and former reality show co-star Paris Hilton took the opportunity to post some adorable throwback photos that have us wanting to binge watch the show, stat.

"Happy Birthday @NicoleRichie! So many special memories since we were little girls! Sending you lots of love, happiness & birthday wishes! Love always Paris," Hilton captioned the composite of two photos of the girls back in the day. But although they may be way younger in the snaps, there's no mistaking the two stars.

But Hilton wasn't the only one to take to Instagram to wish the Candidly Nicoleactress a happy birthday. Richie's husband, Joel Madden, 'grammed a photo of his wife with a blue wig on along with the caption, "Happy Birthday," and a laughing emoji.