diff --git a/include/wx/defs.h b/include/wx/defs.h
index 8612b22274..01e30314cb 100644
--- a/include/wx/defs.h
+++ b/include/wx/defs.h
@@ -163,6 +163,12 @@
 #   endif
 #endif
 
+/* Prevents conflicts between sys/types.h and winsock.h with Cygwin, */
+/* when using Windows sockets. */
+#if defined(__CYGWIN__) && defined(__WINDOWS__)
+#define __USE_W32_SOCKETS
+#endif
+
 /*  ---------------------------------------------------------------------------- */
 /*  wxWidgets version and compatibility defines */
 /*  ---------------------------------------------------------------------------- */
diff --git a/include/wx/msw/gccpriv.h b/include/wx/msw/gccpriv.h
index aee8732ed5..60e3943ea5 100644
--- a/include/wx/msw/gccpriv.h
+++ b/include/wx/msw/gccpriv.h
@@ -83,12 +83,6 @@
     #define __CYGWIN10__
 #endif
 
-/* Prevents conflicts between sys/types.h and winsock.h with Cygwin, */
-/* when using Windows sockets. */
-#if defined(__CYGWIN__)
-    #define __USE_W32_SOCKETS
-#endif
-
 /*
     Traditional MinGW (but not MinGW-w64 nor TDM-GCC) omits many POSIX
     functions from their headers when compiled with __STRICT_ANSI__ defined.
diff --git a/tests/allheaders.cpp b/tests/allheaders.cpp
index 5f8261fd9c..0d30d1c4a6 100644
--- a/tests/allheaders.cpp
+++ b/tests/allheaders.cpp
@@ -45,9 +45,9 @@
 // We have to include this one first in order to check for wxUSE_XXX below.
 #include "wx/setup.h"
 
-// Normally this is done in include/wx/msw/gccpriv.h included from wx/defs.h,
-// but as we don't include it here, we need to do it manually to avoid warnings
-// inside the standard headers included from catch.hpp.
+// Normally this is done in wx/defs.h, but as we don't include it here, we need
+// to do it manually to avoid warnings inside the standard headers included
+// from catch.hpp.
 #if defined(__CYGWIN__) && defined(__WINDOWS__)
     #define __USE_W32_SOCKETS
 #endif