diff --git a/Kernel_23/include/CGAL/Projection_traits_zx_3.h b/Kernel_23/include/CGAL/Projection_traits_zx_3.h
deleted file mode 100644
index ca73f65db4c..00000000000
--- a/Kernel_23/include/CGAL/Projection_traits_zx_3.h
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright (c) 1997-2010  INRIA Sophia-Antipolis (France).
-// All rights reserved.
-//
-// This file is part of CGAL (www.cgal.org); you may redistribute it under
-// the terms of the Q Public License version 1.0.
-// See the file LICENSE.QPL distributed with CGAL.
-//
-// Licensees holding a valid commercial license may use this file in
-// accordance with the commercial license agreement provided with the software.
-//
-// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
-// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
-//
-// $URL$
-// $Id$
-// 
-//
-// Author(s)     : Mariette Yvinec
-
-#ifndef CGAL_PROJECTION_TRAITS_ZX_3_H
-#define CGAL_PROJECTION_TRAITS_ZX_3_H
-
-#include <CGAL/internal/Projection_traits_3.h>
-
-namespace CGAL {
-
-template < class R >
-class Projection_traits_zx_3
-  : public internal::Projection_traits_3<R,1>
-{};
-
-} //namespace CGAL
-
-#endif // CGAL_PROJECTION_TRAITS_ZX_3_H