The present invention relates to a method for compensating for a wavelength mismatch between a readout reference beam and a recording reference beam in a holographic storage system, and to a holographic storage system implementing the method.According to the invention, the wavelength mismatch is determined and the direction of at least part of the readout reference beam relative to a holographic storage medium is adjusted in dependence on the determined wavelength mismatch by defocusing the readout reference beam or by adjusting the focal length of an objective lens for focusing the readout reference beam into the holographic storage medium.