Bigger isn’t always better.

Matthew McConaughey revealed in his new book that downsizing his bed helped him get closer to his wife of 13 years, Camilla Alves — and he doubled down in a subsequent interview.

“The best thing you can / do for your / marriage,” he titled one entry in his new book, “Poems & Prayers.”

“One way to surely / get ahead, / is get rid of that / king-­size mattress, / and sleep in a / queen-­size bed.”

“We have kids and we go to our friend’s house and he has one of these double king-size beds put together and all the kids sleep in the bed,” the “Dallas Buyers Club” actor, 55, told Fox News Digital for an interview published Saturday.

“The wife’s on one side with her side table, and the husband’s on the other side, and it’s great when you got all three kids, but all of a sudden the kids get too big. They’re out of the bed.”

McConaughey recalled being bewildered to wake up to see Alves, 42, on the opposite side of a very large bed.

“I wake up one morning … I’m looking over there and Camilla’s like a football field away man,” he said. “Then you go to bed at night, like you want to snuggle up and …’Well, we’ve got to cover you up. Come about 12 feet and I’ll come 12 feet.’”

The “Interstellar” actor came to the realization that a larger bed was perhaps “not good for the marriage, man.”

“Get rid of that son of a bitch,” he exclaimed. “So we got a queen size where we’re shoulder to shoulder. I’m telling you, it’s good for your marriage.” He added that the improved sleeping arrangement leaves “no room” for kids.

The couple, who celebrated their 13th wedding anniversary in June, married in 2012 and share three children — sons Levi, 17 and Livingston, 12, and daughter Vida, 15.

During a joint 2024 interview, they shared another secret to their lengthy marriage — how they de-escalate their arguments.

“Go and get something sweet,” the “How to Lose a Guy in 10 Days” star said on an episode of the “Your Mama’s Kitchen” podcast.

“A sweet food. It can de-escalate some things, even if it’s a nice piece of chocolate or some ice cream, it can de-escalate,” he explained.