diff --git a/src/lang/spanish.txt b/src/lang/spanish.txt
--- a/src/lang/spanish.txt
+++ b/src/lang/spanish.txt
@@ -2399,6 +2399,8 @@ STR_NEWGRF_SETTINGS_PARAMETER_QUERY                             :{BLACK}Introduce los parámetros del NewGRF
 # NewGRF parameters window
 STR_NEWGRF_PARAMETERS_CAPTION                                   :{WHITE}Cambiar parámetros NewGRF
 STR_NEWGRF_PARAMETERS_CLOSE                                     :{BLACK}Cerrar
+STR_NEWGRF_PARAMETERS_RESET                                     :{BLACK}Reset
+STR_NEWGRF_PARAMETERS_RESET_TOOLTIP                             :{BLACK}Fijar todos los parámetros a su valor por defecto
 STR_NEWGRF_PARAMETERS_DEFAULT_NAME                              :Parámetro {NUM}
 STR_NEWGRF_PARAMETERS_SETTING                                   :{STRING}: {ORANGE}{STRING}