Lewis Hamilton will get a brand new and upgraded MGU-H for the Spanish Grand Prix, which will be his fourth of the season, meaning he will have just one more available before he is hit with a grid penalty.
The Briton suffered a double MGU-H failure at the last two races, leading to a thorough investigation into the cause back at Mercedes Brixworth.
With the team still unsure of the exact cause, they have decided to introduce a new and improved component for the upcoming event, which will be fitted to Hamilton's car for first practice on Friday.
Nico Rosberg will continue to use the previous spec, as it has shown no signs of the problems experienced by team-mate.
Hamilton will have just one more MGU-H available to him before he will be served with a ten-place grid penalty, which with 17 races remaining, will be almost impossible to avoid.