There are two crystallographically independent molecules in the asymmetric unit of the title compound, C13H17N3S, one of them being disordered over the methyl group [site-occupancy ratio = 0.705 (5):0.295 (5)]. The maximum r.m.s. deviations from the mean plane of the non-H atoms for the tetralone fragments amount to 0.4572 (17) and 0.4558 (15) Å. The N-N-C-N fragments are not planar and torsion angles are -9.4 (2) and 8.3 (2)°. In the crystal, the molecules are linked by weak N-H...S interactions into chains along [100] with graph-set motif C(4) and connected by weak N-H...S and C-H...S interactions, forming R21(10) rings. The Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are the H...H (64.20%), H...S (12.60%) and H...C (12.00%) interactions. The crystal packing resembles a herringbone arrangement when viewed along [001].