The mol-ecule of the title compound, C18H13NOS, is build up from two fused six-membered rings, with the heterocyclic component linked to a benzyl-idene group and to a prop-2-yn-1-yl chain. The six-membered heterocycle adopts a distorted screw-boat conformation. The prop-2-yn-1-yl chain is almost perpendicular to the mean plane through benzo-thia-zine as indicated by the C-N-C-C torsion angle of 86.5 (2)°. The dihedral angle between the benzene rings is 47.53 (12)°. There are no specific inter-molecular inter-actions in the crystal packing.