We demonstrate the generation of a supercontinuum spanning more than 1.5 octaves over the 1.2-3.7 mu m range in a silicon nitride waveguide using sub-40-fs pulses at 2.35 mu m generated by a 75 MHz Kerr-lens mode-locked Cr:ZnS laser. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement