This note tackles the output zeroing problem of a square multiple-input-multiple-output plant containing uncertain nonsmooth hysteresis-like nonlinearities in actuator and sensor devices simultaneously. To this purpose, a robust sliding mode controller, based on the output of a reduced order observer, has been designed using it, such control law ensuring both the asymptotical zeroing of the sensing nonlinearities output and the boundedness of the unavailable states. Theoretical results have been validated by simulation.