In the title compound, C14H14O4, the prop-2-yn-yloxy O-C-C C plane [maximum deviation = 0.0116 (12) Å] forms a dihedral angle of 78.44 (9)° with the benzofuran-3(2H)-one ring system. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming a tape along the a-axis direction. C-H⋯O inter-actions are observed between the tapes.