diff --git a/CHANGES b/CHANGES
index fd585d916..d87d5b931 100644
--- a/CHANGES
+++ b/CHANGES
@@ -60,6 +60,8 @@ CHANGES IN FLTK 1.3.4					RELEASED: ??? ?? 2016
 	  or not (STR #3142). It also captures subwindows of GL windows.
 	- Fl::delete_widget() now hides the widget or window immediately
 	  (i.e. when called) - only destruction is delayed as before.
+	- FLTK header files don't expose X11 definitions in user code any more
+	  unless required by including FL/x.H explicitly or implicitly.
 	- The PostScript code output when printing images under Linux/Unix
 	  is quite smaller due to use of lossless compression techniques.
 	- The Linux/Unix printer dialog now uses BSD-style printing commands
diff --git a/FL/fl_utf8.h b/FL/fl_utf8.h
index 1551991b5..2121198df 100644
--- a/FL/fl_utf8.h
+++ b/FL/fl_utf8.h
@@ -60,8 +60,10 @@
 #else /* X11 */
 #  include <sys/types.h>
 #  include <sys/stat.h>
-#  include <X11/Xlocale.h>
-#  include <X11/Xlib.h>
+#  if defined(FL_LIBRARY) /* don't expose X11 headers in user space */
+#    include <X11/Xlocale.h>
+#    include <X11/Xlib.h>
+#  endif /* defined(FL_LIBRARY) -- don't expose X11 headers in user space */
 #  include <locale.h>
 #  define xchar unsigned short
 #endif