75 ILCS 16/15-35

Notwithstanding the provisions of Sections 15-5 through 15-30, 15-40, and 15-45, whenever a municipality included entirely or partially within a library district has annexed or otherwise includes within the municipality's boundaries territory contiguous to the district and not in another public library's taxing district, and the territory has no voters residing in it, the library district by ordinance may annex the territory to the district.