In the title compound, C(8)H(8)N(2)OS, strong intramolecular N-H.O hydrogen bonds [N.O = 2.669 (3) and 2.618 (3) A] form almost planar six-membered rings and enforce the conformation of the molecule. Two kinds of intermolecular N-H.S hydrogen bonds [N.S = 3.309 (3)-3.456 (2) A] between two symmetry-independent molecules form consecutive dimers that expand in ribbons along the [100] direction.