If they haven't upgraded Perl in the past six years, I have trouble believing they're on the edge of their seats waiting to install the latest version of a module from the CPAN.
I may have old Perl versions on some of my servers, that doesn't mean I don't occasionally have to install another CPAN module.
If that won't work because of some critical feature that simply doesn't exist in my version of Perl, then fine... maybe it's time to upgrade. If, on the other hand, it won't work simply because the author decided to require some fancy, superficial feature like say (because he couldn't be bothered to use print with a "\n"; tacked on), then I would advice that author to switch to Python where nobody seems to care about backwards compatibility.
Which, btw, is the number reason I won't go near Python.
Time flies when you don't know what you're doing