Nicole Richie and Joel Madden Engaged

Nicole Richie and Joel Madden are engaged to get married, announced the bride-to-be Monday night during a taping of the Late Show with David Letterman.

The couple began dating in December 2006 and have daughter Harlow, 2, and son, Sparrow, 5 months.

The Good Charlotte rocker announced the news via Twitter on Monday saying, "Yep. I'm engaged. Very happy." Followed by "Yeah we've been engaged for a while so your all kind of late on that. But Thanks for the hooplah all the same."

As recently as October Richie dashed engagement rumors, despite the fact that she and Madden had been living as a family for quite some time.

"One day I would love to get married," said Richie in October. "It's not something we're talking about right now. If my kids ask me to get married, I'd get married."

The couple is expected to tie the knot in the summer.