Infrared spectra of HF (with DF substitution) in solid argon contain weak HF stretching-bending combination bands for N-2-HF, (HF)(2), and (HF)(3) that are higher than the sum of fundamentals. This is in accord with stronger hydrogen bonds upon vibrational excitation of the H-F stretching mode, as observed in the gas phase. Overtone bands were also observed for DF and (DF)(2) in solid argon.