Yes, build a starter, but step it up.
Let's assume it was packaged this time last year, it's probably only ~5% viable (i.e. only 5 billion useful cells in the pack). You need 190 billion yeast cells for a 5 gallon batch. So...
Starter 1: 300ml (on a stir plate) will get you up to somewhere near 50 billion cells
Starter 2: 1000ml (on a stir plate) will get you up to somewhere near 190 billion cells
Don't be tempted just to go for the larger starter straight off the bat, the inoculation rate will be way too low and they'll be no beneficial growth.
Handy calculator to check your numbers:
http://www.brewunited.com/yeast_calculator.php