Nick Lachey thinks his son will grow up to be a doctor.

The American singer and his wife Vanessa Minnillo have 19-month-old Camden together. While the couple might enjoy their life as celebrities, Nick has other ideas for their tot.

"He's becoming a little man. It's crazy. He's growing fast. He's running around and dancing. It's a good time," he gushed to Us Weekly.

"He's going to be a doctor. He's going to cure cancer."

Vanessa added: "He's got so much more to learn and experience... What is the family business? Hosting?"

Nick, 40, released album A Father's Lullaby last year as a tribute to his son. Vanessa revealed that the couple do use the record to help settle their little Camden at night.

When it comes to parenting, she has it all worked out and uses special diapers with an indicator strip that shows when it's damp.

"When [Nick] is like, 'I don't know if [Camden]'s wet or not.' I'm like, 'Look at the strip!' It's daddy-proof," she laughed. "You can't use that excuse."

As the pair have taken to parenting so well, they are keen to expand their brood further.

“Being a father isn’t always easy,” Nick recently revealed to In Touch magazine, “But it’s so rewarding. It’s easily the best thing I ever did.”

“We definitely want to have more, but I don’t have a time frame. It would be fun to have a girl!”