diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6909ee81113a102d37da92a8d8652d73a1ec4bd3..57d10b779dea019e05a218a8f0e965b84988088c 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -507,6 +507,7 @@ struct xdp_link_info {
 struct bpf_xdp_set_link_opts {
 	size_t sz;
 	int old_fd;
+	size_t :0;
 };
 #define bpf_xdp_set_link_opts__last_field old_fd