Cape Town - Kevin Magnussen says there was "never any doubt" that he would re-sign with Haas, putting pen to paper on a new two-year deal.
Haas confirmed an unchanged line up for next year's championship with Magnussen and Romain Grosjean staying on for 2019.
But while the Frenchman's contract is believed to be for one year, for Magnussen it's a new two-year deal.
"I'm extremely happy to continue with Haas for another two years," he said.
"I've had two very good years. Learned a lot and grown a lot as a racing driver and found my place.
"I'm looking forward to two [more] years and maybe more.
"I like having two years because it gives you a long time to figure out what you want to do.
"You don't have to stress about it already in the first year.
"You can get a feeling for what you want to do a year and a half ahead. You can focus on the future without any stress."
The 25-year-old added that both parties agreed a "while ago" to continue the partnership, they just had to finalise the details.
"There's never really been any doubt, it's just contracts are complex," he said. "They take [a] long [time].
"We're a small team, we don't have a big team of people sitting back at the factory who can work on contracts while we're working on F1 cars.
"It kind of has to be done between the races. We both knew what we wanted to do.
"That was really no stress and we didn't have to be one of the first to announce.
"We agreed a while ago that's what we wanted to do."