The thermodynamic dislocation theory developed for nonuniform plastic deformations is used here to simulate the stress-strain curves for crystals subjected to antiplane shear-controlled load reversal. We show that the presence of the positive back stress during the load reversal reduces the magnitude of shear stress required to pull excess dislocations back to the center of the specimen. There, the excess dislocations of opposite signs meet and annihilate each other leading to the Bauschinger effect.