At Warren Buffett’s Berkshire Hathaway (BRK-A, BRK-B), politics and business don’t mix. Even when it comes to hot-button issues like gun control.

“At Berkshire, I’ve expressed my personal views,” Buffett said in an interview with Yahoo Finance editor-in-chief Andy Serwer.

“I don’t put my citizenship in a blind trust. But I also don’t speak for a million Berkshire shareholders. We at the parent company have never given any money to any political campaign or anything of the sort.”

The other side of Berkshire’s decision not to contribute to any political cause is that it also does not tell its wholly-owned units who it can and cannot do business with.

“I’ve got feelings on this,” Buffett said when asked by Yahoo Finance about the National Rifle Association (NRA) and its relationship to big businesses, some of which Berkshire owns stakes in. “But what our shareholders do, our managers do, that is their business.”

Buffett, who supported Hillary Clinton in the 2016 presidential election, said in late February that it would be “ridiculous” for Berkshire not to do business with gun owners.

On Wednesday, high school students across the country walked out of class in a nationwide call to Congress to pass tougher gun laws.

In the wake of the school shooting at Marjory Stoneman Douglas High School in Parkland, Florida, that left 17 people dead, more than a dozen companies publicly cut ties with the NRA as political and corporate life continue to become more intertwined.

Delta (DAL) and Wells Fargo (WFC) are among those companies. Berkshire is the largest investor in Wells Fargo, owning just under 10% of the company, while Delta is among the conglomerate’s 15-largest holdings, with Berkshire owning about $3 billion worth of Delta stock, good for a more than 7% stake in the company.

Following the Parkland shooting, Delta said it would end its contract for discounted rates for NRA members. A Bloomberg report in early March showed that Wells Fargo tops the list of banks arranging financing for gunmakers and serves as the primary banker for the NRA.

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Myles Udland is a writer at Yahoo Finance. Follow him on Twitter @MylesUdland

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