The Oracle of Omaha admits that his investment crystal ball was cloudy on at least two tech companies, Amazon and Google.

Speaking at the annual Berkshire Hathaway shareholder meeting on Saturday, Buffett said he bet wrong when it came to the technology giants, which represent two of the largest companies in the world. The meeting was held before a capacity crowd of approximately 20,000 at the CenturyLink Center in Omaha, Nebraska.

Buffett is considered one of the world’s leading value investors, who specialize in value in companies that are typically under-performing. Buffett has long been wary of technology investments and has also said that he doesn’t consider cryptocurrency as worthy of his money, calling it “rat poison squared” at the Saturday meeting.

But it’s hard to argue with him, given the outsize returns he has delivered to his stockholders over the years.

However, even investing geniuses can make occasional mistakes.

“I made the wrong decisions on Google and Amazon,” he said.  “We’ve looked at it. I made the mistake in not being able to come to a conclusion where I really felt that at the present prices that the prospects were far better than the prices indicated.”

Buffett said Microsoft co-founder Bill Gates had to tell him to stop using the Altavista search engine before he became aware of Google. He said he should have been more aware of the company before its public offering since one of Berkshire’s companies, Geico, was spending a lot of money in advertising.

The investment guru also said he underestimated how rapidly Amazon would disintermediate retail.

“I had very very very high opinion of Jeff’s [Jeff Bezos, CEO of Amazon] ability when I first him, and I underestimated him,” Buffett said. “I’ve watched Amazon from the start. I think what Jeff Bezos has done is something close to a miracle … The problem is when I think something will be a miracle, I tend not to bet on it. It would have been far better obviously if I had some insights into certain businesses.”