Red Bull and its Formula 1 engine supplier Honda have introduced a change to Pierre Gasly's power unit following his exclusion from Azerbaijan Grand Prix qualifying for a fuel flow infringement.
Gasly's results were excluded from the qualifying classification in Baku after his RB15 was found to be in breach of the required fuel flow limit of 100kg per hour.
The Frenchman was already set to begin the race from the pitlane following a Friday weighbridge offence and thus only contested the first segment of qualifying.
He was the fastest of the 20 drivers participating in the segment, having recorded a 1m41.335s that was aided by a tow from Lance Stroll's Racing Point car on the start-finish straight.
Gasly recorded a top speed of around 340km/h in the tow during Q1, and Red Bull has now explained that this led to an unexpected resonance in fuel flow - which took the Frenchman's RB15 over the limit.
The minor issue did not impact Gasly's laptime.
A change, which is understood to be electronics-related, has been introduced to Gasly's Red Bull to ensure there is no repeat offence in the race.
The tweak, made only to Gasly's car and not the three other Honda-supplied cars in F1, would have ordinarily required a pitlane start, but this will make no difference to the Frenchman given his Friday infringement.