1099 R for 401k after-tax rollover to Roth

I rolled over after-tax 401K monies into my Roth IRA after I retired. The 1099 R I received for this has Box 1 (gross distribution) filled in with the actual dollar amount I rolled-over. Then Box 2a (Taxable amount) as zero dollars ($0.00) Also, (Box 7 as "G" code and IRA/SEP/SIMPLE box "checked". This should not be a taxable event per IRS rules yet Turbotax tells me the 1099R is in error with the "G" code and/or IRS/SEP/SIMPLE box checked. My question is this: How should this 1099R be corrected to reflect a non-taxable event such as mine?