When I play tug with my dog she bites my hands. I am sure it’s an accident, but what can I do?

Question from Tim: When I play tug with my 14 month old Malinois, she bites my hands. I'm sure inadvertently. I've tried widening my grip but eventually she still bites it. I really don't think that she's doing this on purpose. She's very intense about tugging on the ball. How can I show her the proper way? I've watched Michael's video on The Power of Playing Tug with Your Dog but I didn't see this addressed in that DVD.