diff --git a/include/wx/msw/setup0.h b/include/wx/msw/setup0.h
index b6133c6cdd..7776e3737c 100644
--- a/include/wx/msw/setup0.h
+++ b/include/wx/msw/setup0.h
@@ -181,6 +181,13 @@
 // global features
 // ----------------------------------------------------------------------------
 
+// Set wxUSE_EXTENDED_RTTI to 1 to use extended RTTI
+//
+// Default is 0
+//
+// Recommended setting: 0
+#define wxUSE_EXTENDED_RTTI 0
+
 // Set wxUSE_STL to 1 to derive wxList(Foo) and wxArray(Foo) from
 // std::list<Foo*> and std::vector<Foo*>, with a compatibility interface,
 // and for wxHashMap to be implemented with templates.