The Hong-Ou-Mandel interferometer is an optical device that allows us to prove the quantum nature of light experimentally via the quantum amplitude superposition of two indistinguishable photons. We have implemented this experiment as an advanced undergraduate laboratory experience. We were able to overcome well-known difficulties using techniques reported recently by Thomas et al (2009 Rev. Sci. Instrum. 80 036101). © 2012 IOP Publishing Ltd.