Top: observed flux in the galaxy J1256+4509 (black curve), error (green), fit obtained letting E_B − V as a free parameter (orange), fits obtained when fixing E_B − V to 0 and 0.2 (blue and red lines) respectively. Bottom: same for the galaxy J1154+2443. Both spectra have been normalized using the median flux between 1090 and 1100 Å. The wavelength regions with Lyα emission (between 1205 to 1225 Å) or low S/N (< 1) are masked during the fitting procedure (see Fig. 1).