diff --git a/boost/polygon/polygon_45_set_data.hpp b/boost/polygon/polygon_45_set_data.hpp
index e541ee5..d3f5e75 100644
--- a/boost/polygon/polygon_45_set_data.hpp
+++ b/boost/polygon/polygon_45_set_data.hpp
@@ -1455,7 +1455,7 @@ namespace boost { namespace polygon{
 
   template <typename cT, typename iT> 
   void get_error_rects_shell(cT& posE, cT& negE, iT beginr, iT endr) {
-    typedef typename iT::value_type Point;
+    typedef typename std::iterator_traits<iT>::value_type Point;
     typedef typename point_traits<Point>::coordinate_type Unit;
     typedef typename coordinate_traits<Unit>::area_type area_type;
     Point pt1, pt2, pt3;
diff --git a/boost/polygon/polygon_traits.hpp b/boost/polygon/polygon_traits.hpp
index 041321d..b1f47fd 100644
--- a/boost/polygon/polygon_traits.hpp
+++ b/boost/polygon/polygon_traits.hpp
@@ -1036,7 +1036,7 @@ namespace boost { namespace polygon{
 
   template <typename iT>
   bool point_sequence_is_45(iT itr, iT itr_end) {
-    typedef typename iT::value_type Point;
+    typedef typename std::iterator_traits<iT>::value_type Point;
     typedef typename point_traits<Point>::coordinate_type Unit;
     if(itr == itr_end) return true;
     Point firstPt = *itr;