diff --git a/libc/kernel/uapi/linux/icmpv6.h b/libc/kernel/uapi/linux/icmpv6.h
index ef73a7c..798a945 100644
--- a/libc/kernel/uapi/linux/icmpv6.h
+++ b/libc/kernel/uapi/linux/icmpv6.h
@@ -77,6 +77,7 @@
 #define ICMPV6_PKT_TOOBIG 2
 #define ICMPV6_TIME_EXCEED 3
 #define ICMPV6_PARAMPROB 4
+#define ICMPV6_ERRMSG_MAX 127
 #define ICMPV6_INFOMSG_MASK 0x80
 #define ICMPV6_ECHO_REQUEST 128
 #define ICMPV6_ECHO_REPLY 129
@@ -91,6 +92,7 @@
 #define ICMPV6_MOBILE_PREFIX_SOL 146
 #define ICMPV6_MOBILE_PREFIX_ADV 147
 #define ICMPV6_MRDISC_ADV 151
+#define ICMPV6_MSG_MAX 255
 #define ICMPV6_NOROUTE 0
 #define ICMPV6_ADM_PROHIBITED 1
 #define ICMPV6_NOT_NEIGHBOUR 2