diff --git a/reactos/include/ndk/lpctypes.h b/reactos/include/ndk/lpctypes.h
index 96bd1b526ce..444130ccc0a 100644
--- a/reactos/include/ndk/lpctypes.h
+++ b/reactos/include/ndk/lpctypes.h
@@ -80,6 +80,11 @@ typedef enum _PORT_INFORMATION_CLASS
 
 #ifdef NTOS_MODE_USER
 
+//
+// Maximum message size that can be sent through an LPC Port without a section
+//
+#define PORT_MAXIMUM_MESSAGE_LENGTH     256
+
 //
 // Portable LPC Types for 32/64-bit compatibility
 //