The invention describes a mercury-free high-intensity gas-discharge lamp (1) comprising a discharge vessel (5) enclosing a fill gas in a discharge chamber (2) and comprising a pair of electrodes (3, 4) extending into the discharge chamber (2), for which lamp (1) the fill gas is derived from a salt fill introduced into the discharge chamber (2) prior to sealing, which salt fill is free of scandium and includes a halide composition comprising a sodium halide to a proportion of at least 65 wt % and at most 97.2 wt %,a thallium halide to a proportion of at least 2 wt % and at most 25 wt %, and an indium halide to a proportion of at least 0.5 wt % and at most 25 wt %. Eliminating the highly reactive scandium from the fill gas significantly improves lumen maintenance.