diff --git a/include/asm-alpha/socket.h b/include/asm-alpha/socket.h
index 1fede7f..08c9793 100644
--- a/include/asm-alpha/socket.h
+++ b/include/asm-alpha/socket.h
@@ -60,4 +60,6 @@
 #define SO_SECURITY_ENCRYPTION_TRANSPORT	20
 #define SO_SECURITY_ENCRYPTION_NETWORK		21
 
+#define SO_MARK			36
+
 #endif /* _ASM_SOCKET_H */