diff --git a/libc/kernel/uapi/linux/xfrm.h b/libc/kernel/uapi/linux/xfrm.h
index b8e79e8..9509efe 100644
--- a/libc/kernel/uapi/linux/xfrm.h
+++ b/libc/kernel/uapi/linux/xfrm.h
@@ -260,6 +260,7 @@
   XFRMA_IF_ID,
   XFRMA_MTIMER_THRESH,
   XFRMA_SA_DIR,
+  XFRMA_NAT_KEEPALIVE_INTERVAL,
   __XFRMA_MAX
 #define XFRMA_OUTPUT_MARK XFRMA_SET_MARK
 #define XFRMA_MAX (__XFRMA_MAX - 1)