diff --git a/.gitattributes b/.gitattributes
index 0ea6b125152..64687188118 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -2423,6 +2423,7 @@ Number_types/include/CGAL/Sqrt_extension/Modular_traits.h -text
 Number_types/include/CGAL/Sqrt_extension/Real_embeddable_traits.h -text
 Number_types/include/CGAL/Sqrt_extension/Scalar_factor_traits.h -text
 Number_types/include/CGAL/Sqrt_extension/Sqrt_extension_type.h -text
+Number_types/include/CGAL/Sqrt_extension/Wang_traits.h -text
 Number_types/include/CGAL/Sqrt_extension/convert_to_bfi.h -text
 Number_types/include/CGAL/Sqrt_extension/io.h -text
 Number_types/include/CGAL/mpfi_coercion_traits.h -text
diff --git a/Number_types/include/CGAL/Sqrt_extension.h b/Number_types/include/CGAL/Sqrt_extension.h
index 38ada00a418..9230cffd981 100644
--- a/Number_types/include/CGAL/Sqrt_extension.h
+++ b/Number_types/include/CGAL/Sqrt_extension.h
@@ -64,6 +64,7 @@ factorization property.
 #include <CGAL/Sqrt_extension/io.h>
 #include <CGAL/Sqrt_extension/Get_arithmetic_kernel.h>
 #include <CGAL/Sqrt_extension/convert_to_bfi.h>
+#include <CGAL/Sqrt_extension/Wang_traits.h>
 
 
 #endif  // CGAL_SQRT_EXTENSION_H
diff --git a/Number_types/include/CGAL/Sqrt_extension/Wang_traits.h b/Number_types/include/CGAL/Sqrt_extension/Wang_traits.h
new file mode 100644
index 00000000000..5f99cb50280
--- /dev/null
+++ b/Number_types/include/CGAL/Sqrt_extension/Wang_traits.h
@@ -0,0 +1,77 @@
+// Copyright (c) 2006-2008 Max-Planck-Institute Saarbruecken (Germany).
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation; version 2.1 of the License.
+// See the file LICENSE.LGPL 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: svn+ssh://hemmer@scm.gforge.inria.fr/svn/cgal/trunk/Number_types/include/CGAL/Sqrt_extension/Algebraic_extension_traits.h $
+// $Id: Algebraic_extension_traits.h 52628 2009-10-20 08:59:26Z lrineau $
+//
+//
+// Author(s)     : Michael Hemmer   <hemmer@mpi-inf.mpg.de>
+
+
+#ifndef CGAL_SQRT_EXTENSION_WANG_TRAITS_H
+#define CGAL_SQRT_EXTENSION_WANG_TRAITS_H
+
+
+#include <CGAL/basic.h>
+#include <CGAL/Sqrt_extension/Sqrt_extension_type.h>
+
+CGAL_BEGIN_NAMESPACE
+namespace internal{
+
+template <class NT_> class Wang_traits; 
+
+template <class AS, class ROOT>
+class Wang_traits< CGAL::Sqrt_extension<AS,ROOT> >{
+    typedef Wang_traits<AS> WT; 
+public:
+    // the supported number type
+    typedef  CGAL::Sqrt_extension<AS,ROOT> NT;
+    // the scalar type (same as Scalar factor traits ?) 
+    typedef typename WT::Scalar Scalar;
+
+    struct Wang { 
+        bool 
+        operator()
+            (const NT& ext, const Scalar& m, NT& n, Scalar& d) const {
+            typename Algebraic_structure_traits<Scalar>::Integral_division idiv;
+            typename WT::Wang wang; 
+            
+            AS     a0,a1;
+            Scalar d0,d1; 
+            ROOT root;
+            n = NT(0);
+            d = Scalar(0);
+            
+            if(!wang(ext.a0(),m,a0,d0)) return false;
+            
+            if(ext.is_extended()){
+                if(!wang(ext.a1(),m,a1,d1)) return false;
+                d  = d0 * idiv(d1,CGAL::gcd(d0,d1));
+                a0 = a0 * idiv(d,d0);
+                a1 = a1 * idiv(d,d1);
+                n  = NT(a0,a1,ext.root());
+            }else{
+                d = d0; 
+                n = NT(a0);
+            }
+            return true; 
+        }
+    };
+};
+
+
+} // namespace internal
+CGAL_END_NAMESPACE
+
+#endif // CGAL_SQRT_EXTENSION_WANG_TRAITS_H
diff --git a/Polynomial/include/CGAL/Polynomial/Wang_traits.h b/Polynomial/include/CGAL/Polynomial/Wang_traits.h
index c520162429e..78e1b042bd6 100644
--- a/Polynomial/include/CGAL/Polynomial/Wang_traits.h
+++ b/Polynomial/include/CGAL/Polynomial/Wang_traits.h
@@ -32,7 +32,6 @@
 namespace CGAL{
 
 // fwd 
-template <class A, class B> class Sqrt_extension;
 template <class A > class Polynomial;
 
 namespace internal{
@@ -65,44 +64,6 @@ public:
     };
 };
 
-template <class AS, class ROOT>
-class Wang_traits< CGAL::Sqrt_extension<AS,ROOT> >{
-    typedef Wang_traits<AS> WT; 
-public:
-    // the supported number type
-    typedef  CGAL::Sqrt_extension<AS,ROOT> NT;
-    // the scalar type (same as Scalar factor traits ?) 
-    typedef typename WT::Scalar Scalar;
-
-    struct Wang { 
-        bool 
-        operator()
-            (const NT& ext, const Scalar& m, NT& n, Scalar& d) const {
-            typename Algebraic_structure_traits<Scalar>::Integral_division idiv;
-            typename WT::Wang wang; 
-            
-            AS     a0,a1;
-            Scalar d0,d1; 
-            ROOT root;
-            n = NT(0);
-            d = Scalar(0);
-            
-            if(!wang(ext.a0(),m,a0,d0)) return false;
-            
-            if(ext.is_extended()){
-                if(!wang(ext.a1(),m,a1,d1)) return false;
-                d  = d0 * idiv(d1,CGAL::gcd(d0,d1));
-                a0 = a0 * idiv(d,d0);
-                a1 = a1 * idiv(d,d1);
-                n  = NT(a0,a1,ext.root());
-            }else{
-                d = d0; 
-                n = NT(a0);
-            }
-            return true; 
-        }
-    };
-};
 
 template <class AS >
 class Wang_traits< Polynomial<AS> >{