Requirement of translation of unrecoverable foreign currency receivables!

There is a case where we have foreign currency prepayments in FS which we have not translated to current exchange rate because according to IAS 21, this is considered a non monetary item! We have decided that the prepayment is not recoverable now and we need to record provision for bad debt in the accounts! Should we translate the prepayment before recording provision equal to the asset while we know the exchange rate has risen materially and would change the expense for provision of bad debt materially?