diff --git a/include/asm-mn10300/socket.h b/include/asm-mn10300/socket.h
index 99ca648b94c54122057342ec4bcef093b0d0fbe6..80af9c4ccad7f05cd09db4d0d212ec2a0753ed04 100644
--- a/include/asm-mn10300/socket.h
+++ b/include/asm-mn10300/socket.h
@@ -52,4 +52,6 @@
 #define SO_TIMESTAMPNS		35
 #define SCM_TIMESTAMPNS		SO_TIMESTAMPNS
 
+#define SO_MARK			36
+
 #endif /* _ASM_SOCKET_H */