diff --git a/Kernel/API/POSIX/sys/socket.h b/Kernel/API/POSIX/sys/socket.h
index e4cdf828d6..c7353bc77b 100644
--- a/Kernel/API/POSIX/sys/socket.h
+++ b/Kernel/API/POSIX/sys/socket.h
@@ -45,6 +45,7 @@ extern "C" {
 #define IPPROTO_TCP 6
 #define IPPROTO_UDP 17
 #define IPPROTO_IPV6 41
+#define IPPROTO_ICMPV6 58
 
 #define MSG_TRUNC 0x1
 #define MSG_CTRUNC 0x2