Pre-fit timing residuals from a 1-month LOFAR campaign on PSR J0034-0534. The individual time-of-arrival measurements reflect the deviations from a Westerbork-derived timing model for this pulsar (which includes astrometric, spin, and orbital parameters), with no additional re-fitting of these parameters. The measurements have an rms of 11 μs, and it is possible that the deviations of individual points reflect small changes in the dispersion and/or scattering measure of the pulsar. In any case, these data clearly demonstrate LOFAR’s capability to do precision pulsar timing.