The alignment of a corner cube affects the measurement of its dihedral angle. For 5 deg of tilt, the error is up to 7%, depending on the orientation of the tilt. A vector model is devised to derive formulas that take misalignment into account for both solid and hollow corner cubes. When the wave-front tilt caused by the dihedral angle error is not much greater than that caused by the surface figure, because of vignetting for a tilting illumination, the surface figure of the cube facet makes varying contributions to the wave-front tilt for different incident angles. Simulations and experimental results are presented.