diff --git a/MdeModulePkg/Include/Library/NetLib.h b/MdeModulePkg/Include/Library/NetLib.h
index 3700105fb8..0a9d03c6e8 100644
--- a/MdeModulePkg/Include/Library/NetLib.h
+++ b/MdeModulePkg/Include/Library/NetLib.h
@@ -51,6 +51,7 @@ typedef UINT16          TCP_PORTNO;
 
 #define  IP6_HOP_BY_HOP        0
 #define  IP6_DESTINATION       60
+#define  IP6_ROUTING           43
 #define  IP6_FRAGMENT          44
 #define  IP6_AH                51
 #define  IP6_ESP               50