Missouri constitution
Article VI: local government
Section 11

2. Upon approval of this amendment by the voters of Missouri the compensation of county officials, or their duly appointed successor, elected at the general election in 1984 or 1986 may be increased during that term in accordance with any law adopted by the general assembly or, in counties which have adopted a charter for their own government, in accordance with such charter, notwithstanding the provisions of section 13 of article VII of the Constitution of Missouri.