820 ILCS 405/1600

Agreement to contributions by employees void. Any agreement by an individual in the employ of any person or concern to pay all or any portion of an employer's contribution, required under this Act from such employer, shall be void, and no employer shall directly or indirectly make or require or accept any deduction from wages to finance the contribution required from him or require or accept any waiver of any right under this Act by an individual in his employ.