215 ILCS 5/447

Any company, other than a stock company, heretofore organized or incorporated under the laws of this State may, without reincorporation, avail itself of all the provisions of this Code by filing with the Director, a certified copy of a resolution adopted by its board of directors, trustees, or other governing body, and in the case of a stock company such certified copy and a certified copy of a resolution adopted by at least two-thirds of its shareholders, accepting the provisions of this Code.