I have a "false" wall. Should I get it reinforced before mounting my tv onto it?

I just bought a 32" Samsung television to mount onto my bedroom wall. We have a professional in to mount it for us, the only thing that concerns me is that he is not going to reinforce our bedroom wall which is only plasterboard and joists. The tv weighs 12kg, should it be reinforced or is it safe to mount it without. (we are paying �200 for the tv to be mounted, have cables hidden, and extra plug socket and aerial socket.)