diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 3c35eb401931f8e312461b88147b2aec59a3bf67..3d690d4e785c3e16c725011cdbcc6cf20f19251d 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