Ferrari's Halo wings were banned for the Monaco Grand Prix following the "dispute over rule interpretation" between the FIA and the Italian team.
Teams were not allowed to use wings in that area, but the FIA sent a directive to the teams in the past week and said they could place the mirror in Halo.
Ferrari was the first team to do this, but there was a wing on the mirror. Ferrari said it was used primarily for the mounting of mirrors.
However, some rival teams have said that this mirror design, including Ferrari's wing, may not be legal.
The FIA closely examined Ferrari's system and explained that the main purpose of the wing was to gain an aerodynamic advantage.
Then he explained that Ferrari could not use it in the next race. This decision will be allowed to use this system this weekend while announcing it.
On Thursday, Nikolas Tombazis, who made the statement after seeing Ferrari's design, agreed that teams would want to gain an aerodynamic advantage when it comes to mirrors.