state tax refund for prior year being taxed, but I itemized that year using sales tax

My state adjusted a refund for a prior year  (2016),  resulting in a State Tax Refund 1099-G this year for a prior year (2016).  Turbo tax is treating this as income.  I did itemize in 2016, but took state sales tax deduction instead of state income tax (because of AMT, it didn't make a difference).   As such, I shouldn't have to pay Federal Tax on the State Refund.    On the State and Local Tax Refund Worksheet, Part VII, the refund for prior year shows up, and column D (Taxable Amount) is the refund amount.  How do I indicate that in 2016 I used Sales Tax and therefore this should be zero?