diff --git a/doc/iterator_adaptor_ref.rst b/doc/iterator_adaptor_ref.rst
index de48fcb..1d13a9c 100644
--- a/doc/iterator_adaptor_ref.rst
+++ b/doc/iterator_adaptor_ref.rst
@@ -19,7 +19,8 @@
       friend class iterator_core_access;
    public:
       iterator_adaptor();
-      explicit iterator_adaptor(Base iter);
+      explicit iterator_adaptor(Base const& iter);
+      typedef Base base_type;
       Base const& base() const;
    protected:
       typedef iterator_adaptor iterator_adaptor\_;
@@ -115,7 +116,7 @@ above are defined as follows:
     ``m_iterator`` default constructed.
 
 
-``explicit iterator_adaptor(Base iter);``
+``explicit iterator_adaptor(Base const& iter);``
 
 :Returns: An instance of ``iterator_adaptor`` with
     ``m_iterator`` copy constructed from ``iter``.
diff --git a/include/boost/iterator/iterator_adaptor.hpp b/include/boost/iterator/iterator_adaptor.hpp
index eabacde..457c439 100644
--- a/include/boost/iterator/iterator_adaptor.hpp
+++ b/include/boost/iterator/iterator_adaptor.hpp
@@ -278,6 +278,8 @@ namespace boost
       {
       }
 
+      typedef Base base_type;
+
       Base const& base() const
         { return m_iterator; }
 
diff --git a/test/iterator_adaptor_test.cpp b/test/iterator_adaptor_test.cpp
index 14b1beb..dddac26 100644
--- a/test/iterator_adaptor_test.cpp
+++ b/test/iterator_adaptor_test.cpp
@@ -316,6 +316,19 @@ main()
       assert((*i).m_x == i->foo());      
   }
 
+  // check that base_type is correct
+  {
+    // Test constant iterator idiom
+    typedef ptr_iterator<int> BaseIter;
+
+    test = static_assert_same<BaseIter::base_type,int*>::value;
+    test = static_assert_same<constant_iterator<BaseIter>::base_type,BaseIter>::value;
+
+    typedef modify_traversal<BaseIter, boost::incrementable_traversal_tag> IncrementableIter;
+
+    test = static_assert_same<IncrementableIter::base_type,BaseIter>::value;
+  }
+
   std::cout << "test successful " << std::endl;
   (void)test;
   return 0;