diff --git a/include/rpcndr.h b/include/rpcndr.h
index ed6cf298d25..d67ceee4ac8 100644
--- a/include/rpcndr.h
+++ b/include/rpcndr.h
@@ -187,6 +187,7 @@ typedef struct _MIDL_STUB_MESSAGE
   int fHasExtensions:1;
   int fHasNewCorrDesc:1;
   int fUnused:10;
+  int fUnused2:16;
   unsigned long dwDestContext;
   void *pvDestContext;
   NDR_SCONTEXT *SavedContextHandles;