Canada Water station will be renamed "Buxton Water" during the London Marathon, Transport for London (TfL) has said.
The renaming - during which all the Canada Water roundels will be replaced, and Buxton Water branding will be put up around the station - is part of plans by TfL to make £3.4bn from "non-fare income" during the next 10 years.
The ad deal, which will take place as thirsty runners race past the tube station on Sunday, is thought to be worth £110,000. Buxton has been the marathon's "official water provider" for two years. This year it will provide runners with water at every mile marker, from mile three to mile 25.
Graeme Craig, TfL's director of commercial development, emphasised the fact the deal was "for one day only".
"This is a significant deal and the revenue will be reinvested back into our network for the benefit of our customers."
Menwhile, Caroline Juin, Nestle Waters UK's head of marketing, pointed out that the branding will "not only showcase our commitment to the event but raises awareness of the importance of drinking enough water, whether it be on your daily commute or running a marathon". Er, quite.