Major GOP donor Charles Koch is dead set on not choosing between Hillary Clinton and Donald Trump in the presidential election.

“But if I had to vote for cancer or heart attack, why would I vote for either?” Koch told Fortune in an interview Monday.

Koch said that “we’re not supporting” the “two people” he sees running for President at this moment. Pressed again to make a choice, he asked, “Why do I have to?”

“Are you going to put a gun to my head?” Koch said.

Of Trump, Koch said he was “sure” the presumptive GOP nominee was “a fine fellow underneath.”

“But when you look at our guiding principles, you see that his guiding principles are in many ways antithetical to them and a great many of his policies are antithetical,” Koch said. He pointed specifically to a Trump trade proposal that Koch called a “monstrosity.”

Koch also rebuked the way the media “spun” an interview he did last April in which he suggested Clinton could possibly be a better president than Trump.

“So the deal is – what I said is, would you ever support her? I said it’s possible if she totally changed everything she stood for. And they spun that around to I might support Hillary,” Koch said. “I’ve got to be more careful of what I say. You can see why all those years I didn’t give interviews.”