Nicole Richie and Joel Madden announce plans to wed on 'Letterman,' Twitter

Nicole Richie and Joel Madden are going to make it official.

The couple confirmed their plans to marry on Monday's episode (Feb. 15) of "The Late Show with David Letterman" and also took to Twitter to confirm the happy news.

After the announcement on "Letterman," Madden tweeted: "Yep. i'm engaged. Very happy. Yeah we've been engaged for a while so your all kind of late on that. But Thanks for the hooplah all the same."

Following the appearance on the late night show, Richie flew solo for dinner at restaurant Abe & Arthur's in New York, according to People.

"She was glowing," a source for the publication says. "She was telling her table how happy she was."

Previously reported on The Dish Rag in June 2008, Richie and Madden told People they didn't have plans to marry in the foreseeable future: "We don't have any plans for that right now. We're just happy, and we're being a family, and that's where we're at right now. But marriage means something different to everyone."

But apparently two years later the happy couple was ready to take the leap. Richie and Madden also share two kids together -- 2-year-old Harlow and 5-month-old Sparrow.

Congratulations!