Gwyneth Paltrow has hinted that she and husband Chris Martin might be adding to their brood one day.

The Iron Man actress and the Coldplay frontman already have two children - eight-year-old daughter Apple and six-year-old son Moses - but it seems they haven't ruled out having another baby, reported People.

Gwyneth, 39, told InStyle magazine: "My brain says, 'Oh, I think I'm done, the kids are so big now, and I don't want to go back to changing diapers.' But a part of me would love to have another.

"Of course, I'm old now!"

The star, who was interviewed by designer Diane von Furstenberg for the magazine's October issue, also revealed that the key to her happy marriage with Chris is laughter and having common interests.

Gwyneth, who married the singer in 2003, said: "We laugh a lot, and at the same jokes. We like the same music and we like to do the same things."