Nicole Richie and Joel Madden's wedding might be sooner than expected - the socialite-turned-jewellery designer is already calling the rocker her husband.

Appearing on late-night U.S. chat show Jimmy Kimmel Live! on Thursday, Richie refused to correct the host when he kept referring to the Good Charlotte star as her husband.

When Kimmel quipped, "Thank you for being here on your husband's 31st birthday..." Richie smiled and responded, "I'm so excited to be spending it with you." The comedian later referred to Madden's twin brother Benji as her brother-in-law.

The host later corrected himself by explaining Richie is engaged to the rocker.

At the Oscars on Sunday, where Madden was the house DJ, Richie was asked about her wedding plans and joked, "It's tomorrow... We actually wanted to do it here."

Nicole Richie Pictures