California Gov. Jerry Brown joked Monday that if Republican front-runner Donald Trump wins the 2016 presidential election, the state will build a wall on its borders — not with Mexico but with U.S. 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, according to the Sacramento Bee. “By the way, that is a joke,” he added. “We don’t like walls, we like bridges.”

Brown was lauding California’s economic progress and the influx of young and promising tech workers. However, the state has experienced net out-migration for decades, especially of middle-class families.

His comments came at a dinner held in Sacramento by the California Labor Federation and State building and the Construction trades council of California. He also mocked former Texas Gov. Rick Perry for his actions against California.

Perry 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, Breitbart reported.

“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.”

The governor didn’t stop at taking shots at Perry. He also criticized “old white guys” for not realizing that their pensions depended on the influx of “young people coming into this country and into this state,” Breitbart said.