Mila Kunis wanted to be the face of Dior because the brand makes her "feel good".
The 28-year-old actress - who followed in the footsteps of 'Black Swan' co-star Natalie Portman to sign up to front the fashion house - admits she has always been "tentative" about modelling but is glad she did so for the French company.
She told ELLE magazine: "I've always been tentative about the idea, but this was an easy decision.
"Why not be a part of a fashion house that I look up to? The truth about Dior is it makes you feel special and I would never want to be part of a brand that didn't make me feel good."
Mila does enjoy fashion, but admits purchasing expensive clothes designed by the Olsen twins can be slightly "insane".
The 'Ted' beauty said: "Those girls make the most beautiful clothes and the most expensive clothes ever. It's insane. I'll have to wear them until the end of time!"