Since its massive fake accounts scandal broke last year, Wells Fargo has been looking to assure customers that it's back on the right track. One very big shareholder factors significantly into that effort: Warren Buffett.
The billionaire Oracle of Omaha is the bank's biggest shareholder through his firm Berkshire Hathaway, which has a 9.6 percent stake in Wells Fargo worth nearly $28.5 billion.
In the past, Buffett publicly has stated that the bank made "a huge mistake" that led to the scandal. Wells had to pay a $190 million fine related to employees creating accounts for customers who never requested them.
On Friday, Wells Fargo CEO Timothy Sloan said Buffett was absolutely correct.
"He's been very direct in terms of some of the mistakes that we made," Sloan told CNBC in an exclusive interview. "I agree with him. We had an incentive program that drove the wrong behavior."
Though he has expressed his displeasure not only with the sales scandal but also the way the bank handled it from a public relations standpoint, Buffett has stood firm in supporting Wells Fargo. He has not sold any of his company's shares.
However, that doesn't mean Wells executives aren't conscious of keeping Buffett and other stakeholders happy going forward. Sloan said he's spoken to Buffett three times since becoming CEO.
"I don't know if I'm going to be able to do anything to assure him," Sloan said. "I think our performance is going to reassure him as to whether or not he should continue as our largest shareholder."