Uma Thurman would have to "send it back" if she had a child without a sense of humour.
The 44-year-old actress is mother to Maya and Levon with her ex-husband Ethan Hawke and also has Luna with her ex-partner Arpad Busson.
Being a mum comes naturally to the star, but she thinks having children who are so fun helps a lot.
"I've never had any problems with disciplining my children. They are so smart and intelligent that I never had trouble communicating with them. They're much smarter than I am and better behaved. And, thank God, they're funny, too. It would be intolerable to me to have a humourless, boring child - I'd have to send it back," she told British magazine Hello!
Maya, 16, and 13-year-old Levon were initially unsure when Uma explained she was pregnant with another baby. But they now view two-year-old Luna as their "little buddy", even if mothering the tot has been quite a challenge.
"It's definitely different. She's a wonderful little tyrant and that's definitely a lesson to me because the first two were so easy. Now I have a kid who bites and scratches and does all these things that I'm not used to. So I'm having to go on the internet and Google two-year-old behaviour. OK, biting and scratching is normal. But she's completely charming," Uma laughed.
The star was also quizzed on her youngest's name, which in full is Rosalind Arusha Arkadina Altalune Florence Thurman-Busson. It generated quite a buzz when it was first announced, and Uma can completely understand why. She's explained how it came about.
"I know what you're asking: 'Why does that poor child have so many names?'" she laughed. "That's from her father. He's from a different culture and has lots of names himself and he liked the idea for her, so I just said, 'OK, go ahead.' We actually call her Luna - she doesn't even know about any of the others. One day she's going to be able to read and she'll look at her passport and go, 'Excuse me, but what is going on here?'"
