Trainers

I must have wide feet because my little toes have worn away the inner lining of one of my faveourite AM1. From the inside, I can now feel the outer suede of the toe box area and would like to get some more use out of them as there's still lots of life in the sole.
What can I put in place to prevent any further wear from the inside? Considering it's quite an awkward place to get to...

Duck tape. Super sticky and resistant. Does everything.