diff --git a/include/wx/msw/setup.h b/include/wx/msw/setup.h
index 77e1649801..7007213758 100644
--- a/include/wx/msw/setup.h
+++ b/include/wx/msw/setup.h
@@ -154,6 +154,10 @@
                                   // but you can't mix them. Set to 1 for <iostream.h>,
                                   // 0 for <iostream>
 
+#define USE_WXCONFIG      1
+                                  // if enabled, compiles built-in OS independent wxConfig
+                                  // class and it's file (any platform) and registry (Win)
+                                  // based implementations
 /*
  * Finer detail
  *