Jenson Button decided to extend his Formula One career into a 17th season after he was convinced by McLaren that their fortunes will improve next term.
Button and his beleaguered McLaren team are in the midst of their worst-ever year, with engine supplier Honda enduring a tortuous return to the grid.
McLaren are ahead of only Manor in the constructors' championship after scoring a paltry 17 points this season.
Button has finished in the top 10 on just two occasions - with a best finish of eighth in Monaco - and hinted he had lost interest in the sport after his fifth retirement of the season in Singapore last month.
It appeared the 35-year-old was set to call time on his world championship-winning career, but McLaren announced last week he would see out the second season of his two-year deal.
Button said: "I had a really good week last week - very positive spending it with a lot of key individuals within the team, the heads of department that are really going to make a difference - so I have real belief it is going to be much better next year, both on the car and engine side, and that's why I want to be racing here next year."
Button, who is taking part in his 283rd grand prix here in Russia, did not fear bringing to an end his Formula One career, but said he did not know whether he would still be at the team beyond next season.
On Thursday, his team-mate Fernando Alonso insisted he would see out his three-year deal with McLaren having claimed after the last race in Japan that he was "unsure" if he'd still be racing in Formula One next season.
Button, the 2009 world champion, added: "The only reason you want to keep racing is to have a chance of being competitive, and obviously we're not there yet, but it will be the case in the future.
"I think the future of the sport is also a lot more exciting than we maybe thought it was a year ago, with people understanding that things need to change. There has been a lot of criticism about the sport in general, but it's nice to see people are taking notice and things are changing.
"As for the future, I don't know if I'll be racing in 2017 or 2018 but it looks very exciting, which is something the sport and the fans should be excited about.
"But we're concentrating on now, and there are going to be lots of changes within the team, with the power unit. This is still a very young partnership and lots will change over the winter and we will be more competitive next year."