diff --git a/currency.c b/currency.c
index bd529f18b8..d62aa2d731 100644
--- a/currency.c
+++ b/currency.c
@@ -84,7 +84,7 @@ uint GetMaskOfAllowedCurrencies(void)
 		if (to_euro == CF_ISEURO && _cur_year < 2000 - MAX_YEAR_BEGIN_REAL) continue;
 		mask |= (1 << i);
 	}
-	mask |= (1 << 23); // always allow custom currency
+	mask |= (1 << CUSTOM_CURRENCY_ID); // always allow custom currency
 	return mask;
 }
 
diff --git a/currency.h b/currency.h
index 596428a400..a94f85eb2c 100644
--- a/currency.h
+++ b/currency.h
@@ -20,7 +20,8 @@ extern CurrencySpec _currency_specs[];
 extern const StringID _currency_string_list[];
 
 // XXX small hack, but makes the rest of the code a bit nicer to read
-#define _custom_currency (_currency_specs[23])
+#define CUSTOM_CURRENCY_ID 23
+#define _custom_currency (_currency_specs[CUSTOM_CURRENCY_ID])
 #define _currency ((const CurrencySpec*)&_currency_specs[_opt_ptr->currency])
 
 uint GetMaskOfAllowedCurrencies(void);
diff --git a/settings.c b/settings.c
index 65e84dfb24..7cb7783c7a 100644
--- a/settings.c
+++ b/settings.c
@@ -1151,7 +1151,7 @@ static const SettingDesc _gameopt_settings[] = {
 	SDT_GENERAL("diff_custom", SDT_INTLIST, SL_ARR, (SLE_FILE_I16 | SLE_VAR_I32), 0, 0, GameOptions, diff, 17, 0, 0, 0, NULL, STR_NULL, NULL, 0, 3),
 	SDT_GENERAL("diff_custom", SDT_INTLIST, SL_ARR, (SLE_FILE_I16 | SLE_VAR_I32), 0, 0, GameOptions, diff, 18, 0, 0, 0, NULL, STR_NULL, NULL, 4, SL_MAX_VERSION),
 	    SDT_VAR(GameOptions, diff_level,SLE_UINT8, 0, 0, 9,0, 9, STR_NULL, NULL),
-	  SDT_OMANY(GameOptions, currency,  SLE_UINT8, N, 0, 0,  23, "GBP|USD|EUR|YEN|ATS|BEF|CHF|CZK|DEM|DKK|ESP|FIM|FRF|GRD|HUF|ISK|ITL|NLG|NOK|PLN|ROL|RUR|SEK|custom", 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|SEK|custom", STR_NULL, NULL),
 	  SDT_OMANY(GameOptions, units,     SLE_UINT8, N, 0, 1,   2, "imperial|metric|si", STR_NULL, NULL),
 	  SDT_OMANY(GameOptions, town_name, SLE_UINT8, 0, 0, 0,  17, "english|french|german|american|latin|silly|swedish|dutch|finnish|polish|slovakish|norwegian|hungarian|austrian|romanian|czech|swiss|danish", STR_NULL, NULL),
 	  SDT_OMANY(GameOptions, landscape, SLE_UINT8, 0, 0, 0,   3, "normal|hilly|desert|candy", STR_NULL, NULL),
diff --git a/settings_gui.c b/settings_gui.c
index a91d076525..2678f5eb08 100644
--- a/settings_gui.c
+++ b/settings_gui.c
@@ -171,8 +171,7 @@ static void GameOptionsWndProc(Window *w, WindowEvent *e)
 			}
 			break;
 		case 5: /* Currency */
-			if (e->dropdown.index == 23)
-				ShowCustCurrency();
+			if (e->dropdown.index == CUSTOM_CURRENCY_ID) ShowCustCurrency();
 			_opt_ptr->currency = e->dropdown.index;
 			MarkWholeScreenDirty();
 			break;