I will present results of the paper by Harris et al. of the first LOFAR observations of the radio jet in the quasar 4C+19.44 with a resolution matching JVLA and X-ray Chandra images. We found that, for several knots along the jet, the radio flux densities measured at hundreds of MHz lie well below the values estimated by extrapolating the GHz spectra. This clearly indicates the presence of radio spectral curvature. I will discuss possible interpretations of the finding.