GC and tips

This is the time of year we get a lot of Gift Cards. A tables check came out to $110. They used a $100 GC. They paid the rest with a CC. The Tip screen options are 15% 18% 20%. But the problem is, the percentage is based on the amount after the GC is used, so in this case, $10. So the automatic tip amount is $1.50, $1.80, $2.00 on a $110 check.

Is there a way to correct this so the tip is based on the check total?