diff --git a/libc/kernel/uapi/linux/sysctl.h b/libc/kernel/uapi/linux/sysctl.h
index eb6e61f..24d8362 100644
--- a/libc/kernel/uapi/linux/sysctl.h
+++ b/libc/kernel/uapi/linux/sysctl.h
@@ -491,7 +491,8 @@
   __NET_IPV6_MAX
 };
 enum {
-  NET_IPV6_ICMP_RATELIMIT = 1
+  NET_IPV6_ICMP_RATELIMIT = 1,
+  NET_IPV6_ICMP_ECHO_IGNORE_ALL = 2
 };
 enum {
   NET_NEIGH_MCAST_SOLICIT = 1,