Return of Principal - REIT

I imported our 1099s from our investment accounts.  Our 1099B  shows a sale of a REIT which is not a sale, but a return of principal.  It shows zero as the quantity sold and "Return of Principal" as additional information for the transactions.  However, TurboTax views it as a sale and requires a cost basis.  How can I enter this correctly so that it is not seen as a taxable event?