Gravitational lensing in wave optics is a rich field combining caustic singularities, general relativity and interference phenomena. We present a detailed evaluation of wave optics effects resulting from the frame-dragging of a rotating star modeled by a Lense-Thirring spacetime. We demonstrate that, contrary to what was previously stated in the literature (see e.g. [C. Baraldo , ]), the spin of the star leaves an intricate imprint on the interference fringes and the caustics of the lensed source. This interference pattern can in principle be used to directly measure the spin of the lens.