Lewis Hamilton has been told he will not be able to use a special helmet design during this weekend's Malaysian Grand Prix.
To celebrate Mercedes title sponsor Petronas' home race, the reigning world champion revealed a new design for the Sepang event.
"I had a special helmet made to celebrate Petronas and Malaysia," said Hamilton. "Due to the FIA's new rule, I can't wear it."
The new rule introduced for this season bans drivers from changing the design of their helmets.
"In order for drivers to be easily distinguished from one another whilst they are on the track, the crash helmet of each driver must be presented in substantially the same livery at every event during a championship season," the rule states.