Joey Fatone believes marriage will "bring out the best" in Justin Timberlake.

Justin proposed to longtime girlfriend Jessica Biel last December.

His former ‘N Sync band member Joey thinks things will continue to go smoothly between the couple once they are officially hitched.

"Not much is going to change,” Joey shared with People magazine.

“He's a great dude, and he's very focused on what he does and everything else, and I'm sure this will bring out the best.”

Joey is no stranger to happy unions.

The 35-year-old musician has been with wife Kelly Baldwin for many years and suspects Justin and Jessica will share a similarly successful relationship.

“He's been with her for a long time, so it's basically a piece of paper," he mused. "That's what me and my wife [Kelly Baldwin] were like, and we've been together over 18 years now."

Joey is currently filming the all-star edition of American reality competition Dancing With the Stars.

He feels better prepared his second time around on the programme.

"I feel great, and my stamina has been better than I expected, and it's been a blast so far," he enthused.