Mark Webber had already signed his new contract for 2012 before the summer speculation stepped into its highest gear.
Throughout the August shutdown, it was not certain whether the Australian would be staying alongside Sebastian Vettel next year, or giving way to a youngster like Toro Rosso's Sebastien Buemi.
In fact, Blick newspaper said Swiss Buemi was "disappointed" with Saturday's official news because he had "secretly expected" Webber's seat.
But birthday boy Webber, 35, said he has known about 2012 for weeks.
"(It was) signed not long ago, I think it was the last race (Hungary), actually, on the Sunday," he said after qualifying third at Spa.
The one year extensions are not too bad for me, and also I think it suits them as well
Red Bull team boss Christian Horner insisted Webber is once again guaranteed equality with Vettel in the new deal.
Webber, meanwhile, was asked whether it is his preference to always sign one-year deals, or the team's.
"Little bit of both, I think," he answered. "The one year extensions are not too bad for me, and also I think it suits them as well. Bit of 50-50."