Paycheck Wizard counts non tax item as gross W2

My company pays me a non taxed per diem for travel on paychecks. I have a category setup in Q that is not assigned to any tax reports as it is non taxable income. When I see the “W2 Gross” line on the paycheck entry it is off (high) by the same amount as the non taxable per diem. How do I get the w2 gross to match the taxable amount in this situation? Everything else is good as far as net pay etc.