diff --git a/libc/kernel/uapi/linux/ndctl.h b/libc/kernel/uapi/linux/ndctl.h
index bb51eea..cfe5c9c 100644
--- a/libc/kernel/uapi/linux/ndctl.h
+++ b/libc/kernel/uapi/linux/ndctl.h
@@ -153,6 +153,7 @@
 enum {
   ND_ARS_VOLATILE = 1,
   ND_ARS_PERSISTENT = 2,
+  ND_CONFIG_LOCKED = 1,
 };
 #define ND_IOCTL 'N'
 #define ND_IOCTL_SMART _IOWR(ND_IOCTL, ND_CMD_SMART, struct nd_cmd_smart)