diff --git a/FL/x.H b/FL/x.H
index 371abdde2..e3191618d 100644
--- a/FL/x.H
+++ b/FL/x.H
@@ -3,7 +3,7 @@
 //
 // X11 header file for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 1998-2016 by Bill Spitzak and others.
+// Copyright 1998-2017 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -26,6 +26,7 @@
 
 #   include <FL/Fl_Export.H>
 #   include <FL/platform_types.h>
+#   include <FL/fl_types.h> // for uchar
 class Fl_Window;
 
 #  ifdef WIN32