Wentworth Miller is apparently a big hit behind bars.

The “Prison Break” star is often asked to sign photos that can be used as prized trade offs in men’s prisons. Ouch.

The 34-year-old admits he receives a lot of fanmail from real-life criminals, who hope Miller will reply with an autographed picture they can swap in jail for restricted goods.

“Apparently, a signed head shot from one of the ‘Prison Break’ cast members will get you a packet of cigarettes on the black market behind bars!”