diff --git a/src/rtnlutil.c b/src/rtnlutil.c
index 567accc8..d20b3284 100644
--- a/src/rtnlutil.c
+++ b/src/rtnlutil.c
@@ -330,7 +330,7 @@ static uint32_t rtnl_route_add(struct l_netlink *rtnl, int ifindex,
 					void *user_data,
 					l_netlink_destroy_func_t destroy)
 {
-	L_AUTO_FREE_VAR(struct rtmsg *, rtmmsg);
+	L_AUTO_FREE_VAR(struct rtmsg *, rtmmsg) = NULL;
 	struct in_addr in_addr;
 	size_t bufsize;
 	void *rta_buf;