Illinois Code § 7

§ 7.

Enforcement. (a) A premarital agreement is not enforceable if the party against whom enforcement is sought proves that: (1) that party did not execute the agreement voluntarily; or (2) the agreement was unconscionable when it was executed and, before execution of the agreement, that party: (i) was not provided a fair and reasonable disclosure of the property or financial obligations of the other party; (ii) did not voluntarily and expressly waive, in writing, any right to disclosure of the property or financial obligations of the other party beyond the disclosure provided; and (iii) did not have, or reasonably could not have had, an adequate knowledge of the property or financial obligations of the other party. (b) If a provision of a premarital agreement modifies or eliminates spousal support and that modification or elimination causes one party to the agreement undue hardship in light of circumstances not reasonably foreseeable at the time of the execution of the agreement, a court, notwithstanding the terms of the agreement, may require the other party to provide support to the extent necessary to avoid such hardship. (c) An issue of unconscionability of a premarital agreement shall be decided by the court as a matter of law. (Source: P.A. 86-966.)