Ferrari and Sauber brought an end to the exhaust blowing saga that marred the British grand prix weekend.
The teams rowed at Silverstone about the FIA's clampdown and how it could be equitably applied to the four engine manufacturer's distinct V8 engines.
Ultimately, Charlie Whiting proposed to scrap the clampdown and simply revert to the Valencia setup, where changing engine settings between qualifying and the race were banned but off-throttle blowing was unrestricted.
Williams initially opposed the reversion but eventually signed the letter of unanimity, leaving Ferrari-powered Ferrari and Sauber yet to agree.
"We thought primarily of the image and the fans of formula one," Sauber managing director Monisha Kaltenborn told Auto Motor und Sport, explaining the Swiss team's eventual change of heart.
"We are glad that we now have an agreement," she added.
In the pages of La Stampa, Ferrari team boss Stefano Domenicali agreed: "These stories, with everyone thinking only of what advantage they can get, are not good.
"For this reason we kept a low profile. Without thinking about what we will or will not lose, we have signed the agreement to return to what we had before Silverstone," he confirmed.