diff --git a/include/wx/defs.h b/include/wx/defs.h
index 85348dd143..31e62731b4 100644
--- a/include/wx/defs.h
+++ b/include/wx/defs.h
@@ -143,7 +143,7 @@
 // "old" GNUWIN32 is the one without Norlander's headers: it lacks the standard
 // Win32 headers and we define the used stuff ourselves for it in
 // wx/msw/gnuwin32/extra.h
-#if defined(__MINGW32__) && !wxUSE_NORLANDER_HEADERS
+#if defined(__GNUWIN32__) && !wxUSE_NORLANDER_HEADERS
     #define __GNUWIN32_OLD__
 #endif