R.I. Gen. Laws § 33-6-2: Creditor attesting.

In case by any will or codicil any real or personal estate shall be charged with any debt or debts, and any creditor whose debt is so charged shall attest the execution of the will or codicil, the creditor, notwithstanding the charge, shall be admitted as a witness to prove the execution of the will or codicil, or to prove the validity or invalidity thereof.