The activist investor is the largest shareholder of Hertz (HTZ) and he recruited Marinello nearly two years ago to turn around the legendary, but struggling car rental company that’s been losing money and market share.

Speaking to Fortune, Marinello says of Icahn, “he’s obviously enormously patient to be suffering through this with us. But at the same time he sees the end goal. He sees the great leadership team we’ve built. He understands the great assets we have and the brand that we have. And he’s a believer.”

Since Marinello took charge in 2017, she has been investing in new information technology, upgrading the company’s fleet of vehicles, partnering with companies like Apple (AAPL) and Aptiv (APTV) that are developing autonomous vehicles and hiring a new leadership team. Still, quarterly profits have been swinging positive and negative at the Estero, Florida company and Hertz stock has declined 15 percent so far this year. Hertz has also been steadily falling on Fortune’s list of the largest companies in America. With revenues of $8.8 billion, it is now ranked at number 335 on the Fortune 500.

Marinello knows that Hertz’s turnaround still needs work. She says the only advice she gets from Icahn is “just move faster.” But she confesses, when it comes to investors, “The need to innovate and quickly launch is something that we probably will never do fast enough, but we’re working on it.”

Watch the video above for more from our interview with Marinello.