The infrared spectra of the monoisotopic species H374Ge79Br and H374Ge81Br in the 750–1000 cm-1region covering the vibrationsv2,v5andv3+v6have been recorded with a resolution of 0·04 cm-1and rotationally analysed. In addition, information concerning the hot band (v3+v5) -v3has been obtained and data onv6and (v3+v6) -v3have been used. Fermi resonance betweenv5andv3+v6has been established with |W356| = 4·4067(7)/4·3055(8) cm-1(79/81Br) and the Coriolisx,yresonance linkingv2withv5has been evaluated.