760 ILCS 3/1324
In disposing of trust property subject to a power of appointment, whether exercisable by a will or an instrument other than a will, a trustee acting in good faith shall have no liability to any appointee or taker in default of appointment for relying upon a will, regardless of whether it was admitted to probate, or an instrument believed to be genuine purporting to exercise a power of appointment or for assuming that there is no will or instrument exercising the power of appointment in the absence of actual knowledge thereof within 3 months of the death of the powerholder, in the case of a will, or 3 months of the last date on which the power of appointment may be exercised, in the case of any other instrument. Nothing in this Section precludes a donor of a power or a trustee from requiring that a will be admitted to probate.
760 ILCS 3/1324