40 ILCS 5/5-147.1

If any widow (1) receives any annuity from the fund, and (2) after January 1, 1983 marries a policeman who is a participant in this fund, and (3) such policeman dies and a second widow's annuity becomes payable, the first widow's annuity provided for such widow shall be cancelled at the time she accepts any payment of the second widow's annuity. Any refund due because of such cancelled annuity shall be paid to the widow.