diff --git a/settings_gui.c b/settings_gui.c
--- a/settings_gui.c
+++ b/settings_gui.c
@@ -1465,7 +1465,7 @@ static void CustCurrencyWndProc(Window *
 
 	case WE_ON_EDIT_TEXT: {
 			int val;
-			byte *b = e->edittext.str;
+			const char *b = e->edittext.str;
 			switch (WP(w,def_d).data_2) {
 				case 0:
 					val = atoi(b);