diff --git a/src/settings_type.h b/src/settings_type.h
--- a/src/settings_type.h
+++ b/src/settings_type.h
@@ -309,6 +309,7 @@ struct GameCreationSettings {
 	byte   water_borders;                    ///< bitset of the borders that are water
 	uint16 custom_town_number;               ///< manually entered number of towns
 	byte   variety;                          ///< variety level applied to TGP
+	byte   custom_terrain_type;              ///< manually entered height for TGP to aim for
 	byte   custom_sea_level;                 ///< manually entered percentage of water in the map
 	byte   min_river_length;                 ///< the minimum river length
 	byte   river_route_random;               ///< the amount of randomicity for the route finding