Justin Bieber thinks Prince William should grow some hair, and be less bald.

In an interview with the U.K.’s Rollercoaster Magazine, the Biebz — who, at one point, was famous for his own hair — asked why the royal prince hasn’t taken care of his thinning hair problem.

“I mean, there are things to prevent that nowadays, like Propecia,” he said. “I don’t know why he doesn’t just get those things, those products. You just take Propecia and your hair grows back. Have you not got it over here?”

Pretty harsh, don’t you think? (Even if the little twerp does have a point)

Prince William has yet to respond to Justin’s left field comment, but we’re pretty sure he’s too busy being married to Kate Middleton to care.