65 ILCS 20/21-7
The compensation of all officers shall be by salary. No officer shall be allowed any fees, perquisites or emoluments or any reward or compensation aside from his salary, but all fees and earnings of his office or department shall be paid by him into the city treasury. The city council shall fix the salaries of all officers, except those who are elected or appointed for a definite term fixed by statute, in the annual appropriation ordinance and those salaries shall not be altered during the same fiscal year. The city council, by ordinance other than the appropriation ordinance, shall fix the compensation of each officer who is elected or appointed for a definite term fixed by statute and his salary shall not be increased or diminished during his term of office. The chairman of the finance committee of the city council shall receive in addition to his or her salary as an alderperson such additional compensation, not exceeding $3,500.00 per annum, as may be provided in the annual appropriation ordinance for his or her services as chairman of said committee.
65 ILCS 20/21-7