JPMorgan Chase chief executive Jamie Dimon criticized regulators, saying some of the steps taken to reform the banking sector since the financial crisis had added more complexity to the system.

“It’s five years after the crisis, OK; we still have not fixed a lot of the things you are talking about. Part of the reason [is] we are trying to do too much too fast,” he said, according CNBC’s website.

Speaking on a panel at the World Economic Forum in Davos, Switzerland, Dimon challenged claims that it is difficult to know whether financial institutions are risky, saying banks aren’t the only businesses that aren’t completely transparent.

“Businesses can be opaque; they’re complex,” he said. “You don’t know how aircraft engines work, either.”

Dimon went on to defend the way banks earn their money.

“We provide a service to you. We make a little money every time we do it. That’s what happens,” said Dimon.

Shares of JPMorgan Chase were trading down 1.3% at $45.95 in mid-morning action on the New York Stock Exchange.

Dimon argued the world economy cannot get out of its current slump without a healthy financial sector and defended JPMorgan’s record during the crisis.

“JPMorgan was not just fair-weather friend, we were there in good times and bad times,” he said.