Originally Posted by
FZRA
Presumably because with a headwind your groundspeed is less; therefore V1 can be increased to take in to account the less stopping distance required if aborting from a lower groundspeed.
The key here is whether your airline has chosen to be go minded or stop minded or somewhere in between. If the preference is to stop then the V1 will be as fast as it can be so a headwind will result in a faster V1 provided it’s not limited by something else. On the other hand, if the preference is to go then there is no reason to increase V1 with a headwind.