diff --git a/src/settings.cpp b/src/settings.cpp
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -1306,7 +1306,8 @@ static const SettingDesc _gameopt_settin
 	    SDT_VAR(GameOptions, diff_level, SLE_UINT8, 0, 0, 0, 0,  3, 0, STR_NULL, NULL),
 	  SDT_OMANY(GameOptions, currency,  SLE_UINT8, N, 0, 0, CUSTOM_CURRENCY_ID, "GBP|USD|EUR|YEN|ATS|BEF|CHF|CZK|DEM|DKK|ESP|FIM|FRF|GRD|HUF|ISK|ITL|NLG|NOK|PLN|ROL|RUR|SIT|SEK|YTL|SKK|BRR|custom", STR_NULL, NULL, NULL),
 	  SDT_OMANY(GameOptions, units,     SLE_UINT8, N, 0, 1,     2, "imperial|metric|si", STR_NULL, NULL, NULL),
-	  SDT_OMANY(GameOptions, town_name, SLE_UINT8, 0, 0, 0,    20, "english|french|german|american|latin|silly|swedish|dutch|finnish|polish|slovakish|norwegian|hungarian|austrian|romanian|czech|swiss|danish|turkish|italian|catalan", STR_NULL, NULL, NULL),
+	/* There are only 21 predefined town_name values (0-20), but you can have more with newgrf action F so allow these bigger values (21-255). Invalid values will fallback to english on use and (undefined string) in GUI. */
+	  SDT_OMANY(GameOptions, town_name, SLE_UINT8, 0, 0, 0,   255, "english|french|german|american|latin|silly|swedish|dutch|finnish|polish|slovakish|norwegian|hungarian|austrian|romanian|czech|swiss|danish|turkish|italian|catalan", STR_NULL, NULL, NULL),
 	  SDT_OMANY(GameOptions, landscape, SLE_UINT8, 0, 0, 0,     3, "temperate|arctic|tropic|toyland", STR_NULL, NULL, ConvertLandscape),
 	    SDT_VAR(GameOptions, snow_line, SLE_UINT8, 0, 0, 7 * TILE_HEIGHT, 2 * TILE_HEIGHT, 13 * TILE_HEIGHT, 0, STR_NULL, NULL),
 	SDT_CONDOMANY(GameOptions,autosave, SLE_UINT8, 0, 22,             N, 0, 0, 0, "", STR_NULL, NULL, NULL),