diff --git a/src/invent.c b/src/invent.c
index b349c748f..2eb2291e1 100644
--- a/src/invent.c
+++ b/src/invent.c
@@ -577,7 +577,7 @@ const char *
 currency(amount)
 long amount;
 {
-	if (amount == 1) return "zorkmid";
+	if (amount == 1L) return "zorkmid";
 	else return "zorkmids";
 }