diff --git a/libc/kernel/uapi/linux/neighbour.h b/libc/kernel/uapi/linux/neighbour.h
index 6329211..4ce4736 100644
--- a/libc/kernel/uapi/linux/neighbour.h
+++ b/libc/kernel/uapi/linux/neighbour.h
@@ -42,6 +42,7 @@
   NDA_MASTER,
   NDA_LINK_NETNSID,
   NDA_SRC_VNI,
+  NDA_PROTOCOL,
   __NDA_MAX
 };
 #define NDA_MAX (__NDA_MAX - 1)