Comparison between the flux measured with XID+ using the HELP and LOFAR prior lists. The colour shows the average distance from the LOFAR source for all sources in that bin (and hence the centre of the rerun region). We note the asymmetry about the x = y line on the right hand side of the plot where sources are brighter with the HELP prior compared to the LOFAR prior. This discrepancy is caused by the inclusion of the radio source in the LOFAR prior that causes sources in the HELP prior to have less flux assigned to them. The flux measurement from the LOFAR prior list is consistent with the measurement using the HELP prior list.