diff -uNr libX11-1.3.6.orig//configure.ac libX11-1.3.6/configure.ac
--- libX11-1.3.6.orig//configure.ac	2010-09-20 08:04:16.000000000 +0200
+++ libX11-1.3.6/configure.ac	2010-09-28 16:29:26.000000000 +0200
@@ -355,7 +355,14 @@
 # Find keysymdef.h
 #
 AC_MSG_CHECKING([keysym definitions])
-KEYSYMDEFDIR=`$PKG_CONFIG --variable=includedir xproto`/X11
+AC_ARG_WITH(keysymdefdir,
+        AC_HELP_STRING([--with-keysymdefdir=DIR], [The location of keysymdef.h]),
+        KEYSYMDEFDIR=$withval, KEYSYMDEFDIR="")
+
+if test x$KEYSYMDEFDIR = x; then
+	KEYSYMDEFDIR=`$PKG_CONFIG --variable=includedir xproto`/X11
+fi
+
 FILES="keysymdef.h XF86keysym.h Sunkeysym.h DECkeysym.h HPkeysym.h"
 for i in $FILES; do
     if test -f "$KEYSYMDEFDIR/$i"; then
