Boeing’s CEO says Boeing cut a bad deal when it agreed to produce two new Air Force One jets.

CEO David Calhoun said Wednesday that Boeing probably should not have taken the fixed-cost contract, which makes the company responsible for cost overruns. But, he says, it was a public negotiation and the company took some risks.

Boeing negotiated the $3.9 billion deal with former President Donald Trump, who took a keen interest in the presidential planes. It’s still not clear what the paint job on the new planes will look like.