Empirical mass-loss rate versus luminosity for the Galactic WN stars. Labels refer to the WR catalog numbers; if printed with slanted font, their Gaia measurement is flagged with a significant astrometric excess noise (see Sect. 3). The red symbols refer to stars with detectable hydrogen, while green symbols denote hydrogen-free stars (see inlet and caption of Fig. 2 for more details). Neither group follows a tight Ṁ − L relation. The thick green and red lines are linear regressions to the stars without and with hydrogen, respectively. The gray dotted lines denote the corresponding empirical relations from Nugis & Lamers (2000) for hydrogen-free WN stars (upper line) and for a hydrogen mass fraction of 40% (lower line).