Ferrari boss Maurizio Arrivabene has demanded an urgent revision to his team's wheelnut design following the problem that cost Sebastian Vettel a podium finish at the Austrian Grand Prix.
Vettel had been Mercedes' main challenger at the Red Bull Ring, but dropped behind Williams' Felipe Massa after losing around 10 seconds thanks to a pitstop drama when his crew could not fit his right rear wheel.
Arrivabene made clear that the matter was not related to a mechanic's error, but instead had to do with the inset wheelnut design.
Speaking about what happened, he said: "I have to say that Sebastian made a great race. I have to say Mercedes are still strong.
"But we threw away one more time for a stupid piece that we need to fix as soon as possible. This is not the first time and it is not acceptable."
He added: "It was a problem with the wheelnut. It is not the first time so we have now to make sure that it does not happen again.
"It was not a problem of the mechanics – it was our problem and we have to make sure that we fix it."
Raikkonen issue baffling
Arrivabene also said that there was no obvious explanation for why Kimi Raikkonen had suffered the excessive wheelspin out of Turn 2 that led to his collision with Fernando Alonso.
When asked if a technical fault could have caused it, Arrivabene: "We have just had the briefing now, and honestly I don't think so.
"There is no images on the camera of Alonso, so we have to trust Kimi who said that the car had wheelspin. That is it."