Section 755 ILCS 5/6-11 - Omitted or unnotified heir or legatee(a) If it appears after entry of an order admitting or denying admission of a will to probate that an heir or legatee was omitted from the petition to admit the will to probate or, if included in the petition, that notice to him was not mailed or published as provided in Section 6-10 or 6-20, whichever is applicable, and that no waiver of notice was filed by the omitted or unnotified heir or legatee, an amended petition shall be filed under Section 6-2 or 6-20 which shall include the omitted or unnotified heir or legatee.(b) If the amended petition is filed under Section 6-2, a copy of the amended petition and the order admitting or denying admission of the will to probate or notice thereof shall be mailed to or published for the omitted or unnotified person as provided in Section 6-10, in the same manner as if the order were entered at the time the amended petition was filed. The original order admitting or denying admission of the will to probate is effective as to the omitted or unnotified person as of the date the amended petition is filed and it is effective as to all other persons, including creditors, as of the date of its entry.(c) If the amended petition is filed under Section 6-20, notice of the hearing on the amended petition shall be mailed or published, as provided in Section 6-20, to or for the omitted or unnotified person and to all persons included in any prior petition. In the absence of objections by the omitted or unnotified person, evidence received at the hearing on the original petition to admit the will to probate constitutes prima facie proof of the execution of the will at the hearing on the amended petition. An order admitting the will to probate on an amended petition filed under Section 6-20 is effective as to the omitted or unnotified person as of the date of its entry, but the original order admitting the will to probate is effective as to all other persons, including creditors, as of the date of its entry.