The FIA has banned drivers from using the 'DRS' overtaking wing in the Monaco tunnel this weekend.
The in-race overtaking zone spans just 300 metres on the start-finish straight, but the rear wing system can be used by drivers anywhere else on the twisty street circuit in practice and qualifying.
On safety grounds, however, the first exception of the season has been applied for the famous tunnel, which is technically not a straight but a fast right-hand bend.
The ban was confirmed by Charlie Whiting in a letter to Grand Prix Drivers' Association members, according to the Telegraph.
"We were made aware of drivers' concerns about using it and I've spoken to the drivers a few times about it, and it was quite clear the majority of them would prefer to not use it in Monaco," he told reporters last weekend in Spain.
Not everyone agrees with the drivers, however, including Renault team boss Eric Boullier.
The driver has to judge where he can safely activate the DRS
"The driver has to judge where he can safely activate the DRS," said the Frenchman.
But former driver David Coulthard thinks the GPDA and the FIA are right in this case.
"That (a ban) seems like a sensible compromise. With the marbles that these tyres are producing, to venture off the racing line in that confined space could prove catastrophic.
"Better not to have the temptation," the 13-time Grand Prix wrote in his column for the Telegraph.