Lil Wayne is headed to the big house.

The troubled rapper pleaded guilty to felony gun possession charges Thursday, agreeing to spend a year behind bars.

Wayne, whose real name is Dwayne Carter, 27, was hit with a pair of charges after a loaded 9-mm. gun was discovered in his tour bus two years ago.

He pleaded guilty to attempted possession of a weapon in the second degree, sparing him a possible 3 1/2-to-7-year prison sentence.

The surprise plea came in the middle of what was expected to be a lengthy pre-trial hearing.

"Yes, sir," Carter, wearing black jeans and a white T-shirt under a blue, fur-lined coat, said when asked if he was ready to plea.

 Justice Charles Solomon called it "a greatly reduced sentence."

Carter, who is out on bail, left the court with a heavily blinged-out entourage.

He will be sentenced in February.