A gantry crane adapter for a two-post lift includes a pair of angle brackets, each of which has a first, horizontal leg and second, vertical leg. The first leg includes an aperture, and a short hook extends in parallel, spaced relation along an outer surface of the second leg. The hook of each bracket is received in the slot in a carriage in a respective post of the two-post lift to removably connect each bracket to the respective carriage, with the first, horizontal legs of the respective brackets projecting toward each other. A load bearing beam is positioned across the brackets such that an internally threaded boss at each end of the beam is received in an aperture in a respective bracket, and a bolt with a washer is threaded down into the boss, to support and retain the load bearing beam across the angle brackets.