A Donald Trump presidency would apparently spur a lot of new construction.

In response to Trump’s insistence that he would build a big, “beautiful” wall along the U.S. border with Mexico, California Gov. Jerry Brown (D) said Monday that his state would have to build a wall around its own perimeter if Trump took the White House.

“We’d have to build a wall around California to defend ourselves from the rest of this country,” Brown said, according to the Sacramento Bee. “By the way that is a joke. We don’t like walls, we like bridges.”

The Bee reported that Brown was speaking at a dinner in Sacramento for the California Labor Federation and State Building and Construction Trades Council of California.

Though Brown was joking, he condemned the possibility of a new border wall in similarly strong terms in an interview with Bloomberg News earlier this month.

Calling the idea “absolutely preposterous”, Brown said: “It would create such tension with our closest neighbor that, probably, a dumber idea I can’t imagine.”

During his speech in Sacramento, the California governor pointed to the economic benefits of immigration.

“Some of these old white guys ought to recognize that the whole pension system would collapse if we didn’t have a bunch of young people coming into this country and into this state,” Brown said. “They’re not all coming from here. They’re coming from other places.”

California has 10 million immigrants—far more than any other state. Brown has approved a slew of measures aimed at improving the lives of his state’s large immigrant population, including granting driver’s licenses to undocumented immigrants and extending public financial aid to undocumented college students.