diff --git a/sys/netinet/libalias/alias_skinny.c b/sys/netinet/libalias/alias_skinny.c
--- a/sys/netinet/libalias/alias_skinny.c
+++ b/sys/netinet/libalias/alias_skinny.c
@@ -230,7 +230,7 @@
     struct alias_link *lnk, u_int32_t localIpAddr,
     ConvDirection direction)
 {
-	struct in_addr dst, src;
+	struct in_addr dst __unused, src __unused;
 
 	(void)pip;
 	(void)tc;