diff --git a/include/wx/region.h b/include/wx/region.h
index 2cde039eb6..a92ccce90b 100644
--- a/include/wx/region.h
+++ b/include/wx/region.h
@@ -1,24 +1,24 @@
 #ifndef _WX_REGION_H_BASE_
 #define _WX_REGION_H_BASE_
 
+#include "wx/colour.h"
+
 #if defined(__PALMOS__)
-#include "wx/palmos/region.h"
+    #include "wx/palmos/region.h"
 #elif defined(__WXMSW__)
-#include "wx/msw/region.h"
-#elif defined(__WXMOTIF__)
-#include "wx/x11/region.h"
+    #include "wx/msw/region.h"
 #elif defined(__WXGTK__)
-#include "wx/gtk/region.h"
-#elif defined(__WXX11__)
-#include "wx/x11/region.h"
+    #include "wx/gtk/region.h"
+#elif defined(__WXMOTIF__) || defined(__WXX11__)
+    #include "wx/x11/region.h"
 #elif defined(__WXMGL__)
-#include "wx/mgl/region.h"
+    #include "wx/mgl/region.h"
 #elif defined(__WXMAC__)
-#include "wx/mac/region.h"
+    #include "wx/mac/region.h"
 #elif defined(__WXCOCOA__)
-#include "wx/cocoa/region.h"
+    #include "wx/cocoa/region.h"
 #elif defined(__WXPM__)
-#include "wx/os2/region.h"
+    #include "wx/os2/region.h"
 #endif
 
 #endif