diff --git a/reactos/include/ndk/lpctypes.h b/reactos/include/ndk/lpctypes.h
index e293fb49e0b..ef1abc12014 100644
--- a/reactos/include/ndk/lpctypes.h
+++ b/reactos/include/ndk/lpctypes.h
@@ -9,6 +9,8 @@
 #ifndef _LPCTYPES_H
 #define _LPCTYPES_H
 
+#define PORT_MESSAGE_TYPE(m) ((m).Header.MessageType)
+
 /* DEPENDENCIES **************************************************************/
 
 /* EXPORTED DATA *************************************************************/