Tesla’s Model S just got a little faster.

According to Bloomberg, a new software update will allow owners to upgrade their engines to go from 0-60 mph in only 2.4 seconds—a fraction of a second faster than the Bugatti Veyron Grand Sport Vitesse.

Here’s the catch: the feature is hidden.

It’s what’s known in the tech industry as an “Easter egg,” and in true Easter egg fashion, users will have to figure out how to activate the feature before using it.

This isn’t the first Easter Egg Tesla has hidden in its vehicles; a previous Easter Egg allowed users to change their cars’ display to resemble the control panel of the Lotus James Bond used in the film The Spy Who Loved Me.

For more on Tesla, watch Fortune’s video:

This is, however, the first time Tesla has released an Easter Egg that can change the performance of its cars. Current versions of Tesla’s award-winning vehicle was already reportedly the world’s fastest car, clocking 0-60 mph in 2.5 seconds, the company says.

Elon Musk revealed the update on Twitter on Wednesday.

The update is set to be released in December.