After 12 years together, Gavin Rossdale says his marriage to Gwen Stefani is “rock solid,” but his kids are another story.

“We have so many kids now, no matter what, it’s rock solid,” the Bush frontman, 48, told Us Weekly on Saturday.

The couple has three kids together: Kingston, 8, Zuma, 5, and Apollo, 3 months.

“Oh, they’re terrible! So naughty,” said Rossdale.

The family’s newest addition, Apollo, seems to be calm — for now.

“He’s 3 months old, so he’s pretty chilled out,” Rossdale said. “We’re very proud of him. He’s a great kid, [but] he’ll be naughty soon enough.”