If you sold all or part of these shares in 2017, then you will use your new cost basis when reporting the sale to the IRS.
In your Federal return, under Wages & Income, scroll down to Investment income and Start or Revisit Stocks, Mutual Funds, Bonds, Other. Edit the correct transaction. You will enter your new/adjusted cost basis in Box 1e.
Be sure to keep your calculations in your records.
