Nicole Richie and her Good Charlotte rocker boyfriend, Joel Madden, are getting married.
Richie, 28, made the announcement Monday on The Late Show with David Letterman.
"Yep. i'm engaged. Very happy," wrote Madden, 30, on Twitter Monday. "Yeah we've been engaged for a while so your all kind of late on that. But Thanks for the hooplah all the same."
A source tells UsMagazine.com, "Nicole and Joel are in the process of planning the wedding. She's very involved in every detail. She’s thrilled."
The couple is expected to tie the knot in the summer.
Richie and Madden started dating in December 2006 and have two children together: Harlow, 2, and Sparrow, 5 months.
Last year, Richie told CNN's Larry King that she was in no rush to make it official with Madden.
"I think for both of us, we are going to do it because we want to, not because that's what you do," said Richie. "We're going to do it when the time's right."
Richie's rep could not be reached for comment.