6-(1H-Tetrazol-5-yl)-1H-indole monohydrate

In the title compound, C₉H₇N₅· H₂O, the tetrazole ring forms a dihedral angle of 1.82 (1)° with the mean plane of the indole fragment. In the crystal, molecules are linked by intermolecular O - H⋯N, N - H⋯O and N - H⋯N hydrogen bonds into a two-dimensional network parallel to (100). Addtional stabilization is provide by weak π-π interactions with a centroid-centroid distance of 3.698 (2) Å.