California Gov. Jerry Brown joked on Monday that if Republican frontrunner Donald J. Trump wins the 2016 election, the state would have to erect a wall — not on its border with Mexico, but its borders with other states.

“If Trump were ever elected, we’d have to build a wall around California to defend ourselves from the rest of this country,” he said at a dinner held in Sacramento by the California Labor Federation and State Building and Construction Trades Council of California, according to the Sacramento Bee. “By the way that is a joke,” he added. “We don’t like walls, we like bridges.”

Brown was touting the state’s economic progress, and the influx of young, talented tech workers — though the state has experienced net out-migration for decades, especially of middle-class families.

The governor blasted “old white guys” for not recognizing that their pensions depended on the influx of “young people coming into this country and into this state.”

He also mocked former Texas Gov. Rick Perry, who became famous during his 14-year tenure as Texas governor for recruiting new businesses to move from California to low-tax, low-regulation, high-growth Texas.

“If I asked you who was that governor, there aren’t 50 people in this room that could even tell me his damn name,” Brown said, according to the Bee. “And people who attack California, they do become anonymous and forgotten. Rightfully so.”