Fans of Doctor Who star David Tennant have been told they can't ask him to sign anything to do with the sci-fi show while he's appearing in a play.
Tennant is starring in Hamlet, and the play's organisers said people were bringing so much Doctor Who stuff to be signed that something had to be done.
So from now on only programmes and other Hamlet merchandise can be signed at the stage door.
The play is being put on by the Royal Shakespeare Company in Stratford.
But it's not just David Tennant who's attracting unwanted attention from sci-fi fans.
His co-star is Patrick Stewart, who appeared in Star Trek: The Next Generation a few years ago.
His fans have also been told not to bring anything sci-fi-related to the theatre.