It is shown that a cube beam splitter can serve as a single-element birefringence-sensitive interferometer. The polarization-masked beam splitter is oriented as in Gate’s Interferometer i.e., the beam splitting interface is parallel to the incident plane beam. The output consists of a pair of collinearly propagating orthogonally polarized beams which intercepts the birefringent sample placed before a linear polarizer. It is interesting to note that in the proposed method, measurement of birefringence remains unaffected by any phase non-uniformity that might be present in the sample.