Matt Damon took action to improve his sperm

Matt Damon quit smoking to improve his sperm.

The actor, who already has three kids with wife Luciana Bozán Barroso, has decided to clear out his system before having more kids.

“I remember my brother gave up before he had kids and he said: “I’m going to give myself six months or a year to clear out my system before I, you know…'” the 42-year-old said.

“Whether there’s any wisdom to your sperm-carrying, your system being somehow cleaner, but that was his thing and I remember thinking: ‘Yeah, I’ll do that, too’.

“Lucy and I knew we’d be having more kids and that process started a year later.”