The title compound, C₄H₆N₂S₃, has two very similar molecules per asymmetric unit. The nine non-H atoms in each molecule are coplanar, both having comparable r.m.s. deviations of 0.002 Å. The main interest in the rather simple structure resides in a survey of very weak (in some cases, borderline) non-bonding interactions of various kinds, viz. S⋯S, C–H⋯π, π–π [centroid-centroid distance = 3.8958 (13) Å] and C–S⋯π [3.7271 (11) Å], which act as the major driving force for the arrangement of molecules in the structure. The role of long, though highly directional, S⋯S contacts (d > 3.60 Å), and their relevance to the stability of the structure is discussed.