Magnet unit (10, 20) for a sensor device for acquiring a measurement variable which characterizes a rotation state of a steering shaft of a motor vehicle, - wherein the magnet unit (10, 20) has a sleeve and a magnet element which is connected in a positively locking fashion to the sleeve, - wherein the sleeve has a sleeve connecting section which extends in the axial direction and has an inner face for connecting to the magnet element and a socket-shaped sleeve attachment section for connecting the magnet unit (10, 20) to a first part of the steering shaft, - wherein the magnet element has a magnet element connecting section which extends in the axial direction and has an outer face for connecting to the sleeve and a magnetically effective magnet section, - wherein the magnet element and the sleeve are connected by means of at least one positively locking connection between the magnet element connecting section and the sleeve connecting section, - wherein the sleeve connecting section and the magnet element connecting section are arranged in an overlapping fashion in the axial direction, and the outer face of the magnet element connecting section bears on the inner face of the sleeve connecting section, and - wherein the sleeve and the magnet element have different coefficients of thermal expansion, wherein the coefficient of thermal longitudinal expansion and/or the coefficient of thermal volume expansion of the magnet element are/is preferably greater than the coefficient of thermal longitudinal expansion and/or the coefficient of thermal volume expansion of the sleeve, and wherein in particular the sleeve and the magnet element are embodied in such a way that in a reference state the positively locking connection is free of play in a tangential direction at a reference ambient temperature. - wherein the magnet unit (10, 20) has a sleeve and a magnet element which is connected in a positively locking fashion to the sleeve, - wherein the sleeve has a sleeve connecting section which extends in the axial direction and has an inner face for connecting to the magnet element and a socket-shaped sleeve attachment section for connecting the magnet unit (10, 20) to a first part of the steering shaft, - wherein the magnet element has a magnet element connecting section which extends in the axial direction and has an outer face for connecting to the sleeve and a magnetically effective magnet section, - wherein the magnet element and the sleeve are connected by means of at least one positively locking connection between the magnet element connecting section and the sleeve connecting section, - wherein the sleeve connecting section and the magnet element connecting section are arranged in an overlapping fashion in the axial direction, and the outer face of the magnet element connecting section bears on the inner face of the sleeve connecting section, and - wherein the sleeve and the magnet element have different coefficients of thermal expansion, wherein the coefficient of thermal longitudinal expansion and/or the coefficient of thermal volume expansion of the magnet element are/is preferably greater than the coefficient of thermal longitudinal expansion and/or the coefficient of thermal volume expansion of the sleeve, and wherein in particular the sleeve and the magnet element are embodied in such a way that in a reference state the positively locking connection is free of play in a tangential direction at a reference ambient temperature.