Abstract: A method and apparatus for correcting thermally induced errors in the operation of a magnetostrictive linear displacement transducer used to monitor the piston position in a hydraulic cylinder. The transducer includes a processing head on one end of the cylinder, a waveguide extending from the processing head and a permanent magnet which encircles the waveguide and travels with the piston. Temperature compensation is provided by a washer which is beveled on its outside edge and a pair of rings which are beveled to mate with the bevels on the washer. The rings have a lower coefficient of thermal expansion than the washer to effect axial shifting of the magnet when the temperature changes in order to compensate for speed change in the waveguide signals with temperature changes.