Impact of the carbon abundance of a star on the derived Pristine photometric metallicities. The difference between the photometric metallicities from the Pristine-Gaia synthetic catalogue and the spectroscopic metallicities from the SAGA database is plotted against the spectroscopic effective temperature and color-coded by the carbon abundance, [C/Fe], Stars that are strongly carbon-enhanced show a clear bias and have overestimated Pristine metallicities, especially for lower T_eff.