diff --git a/include/boost/detail/shared_count.hpp b/include/boost/detail/shared_count.hpp
index cd5ae8f..b47fe62 100644
--- a/include/boost/detail/shared_count.hpp
+++ b/include/boost/detail/shared_count.hpp
@@ -219,6 +219,8 @@ private:
     counted_base_impl(counted_base_impl const &);
     counted_base_impl & operator= (counted_base_impl const &);
 
+    typedef counted_base_impl<P, D> this_type;
+
 public:
 
     // pre: initial_use_count <= initial_weak_count, d(p) must not throw
@@ -232,6 +234,20 @@ public:
     {
         del(ptr);
     }
+
+#if defined(BOOST_SP_USE_STD_ALLOCATOR)
+
+    void * operator new(std::size_t)
+    {
+        return std::allocator<this_type>().allocate(1, static_cast<this_type *>(0));
+    }
+
+    void operator delete(void * p)
+    {
+        std::allocator<this_type>().deallocate(static_cast<this_type *>(p), 1);
+    }
+
+#endif
 };
 
 class weak_count;
diff --git a/shared_ptr_alloc_test.cpp b/shared_ptr_alloc_test.cpp
new file mode 100644
index 0000000..079dde7
--- /dev/null
+++ b/shared_ptr_alloc_test.cpp
@@ -0,0 +1,94 @@
+//
+//  shared_ptr_alloc_test.cpp - use to evaluate the impact of count allocations
+//
+//  Copyright (c) 2002 Peter Dimov and Multi Media Ltd.
+//
+//  Permission to copy, use, modify, sell and distribute this software
+//  is granted provided this copyright notice appears in all copies.
+//  This software is provided "as is" without express or implied
+//  warranty, and with no claim as to its suitability for any purpose.
+//
+
+#include <boost/shared_ptr.hpp>
+#include <boost/config.hpp>
+
+#include <iostream>
+#include <vector>
+#include <ctime>
+#include <memory>
+
+int const n = 1024 * 1024;
+
+template<class T> void test(T * = 0)
+{
+    std::vector< boost::shared_ptr<T> > v;
+
+    std::clock_t t = std::clock();
+
+    for(int i = 0; i < n; ++i)
+    {
+        boost::shared_ptr<T> pi(new T(i));
+        v.push_back(pi);
+    }
+
+    t = std::clock() - t;
+
+    std::cout << static_cast<double>(t) / CLOCKS_PER_SEC << '\n';
+}
+
+class X
+{
+public:
+
+    explicit X(int n): n_(n)
+    {
+    }
+
+    void * operator new(std::size_t)
+    {
+        return std::allocator<X>().allocate(1, static_cast<X*>(0));
+    }
+
+    void operator delete(void * p)
+    {
+        std::allocator<X>().deallocate(static_cast<X*>(p), 1);
+    }
+
+private:
+
+    X(X const &);
+    X & operator=(X const &);
+
+    int n_;
+};
+
+int main()
+{
+    std::cout << BOOST_COMPILER "\n";
+    std::cout << BOOST_PLATFORM "\n";
+    std::cout << BOOST_STDLIB "\n";
+
+#if defined(BOOST_HAS_THREADS)
+    std::cout << "BOOST_HAS_THREADS: (defined)\n";
+#else
+    std::cout << "BOOST_HAS_THREADS: (not defined)\n";
+#endif
+
+#if defined(BOOST_SP_USE_STD_ALLOCATOR)
+    std::cout << "BOOST_SP_USE_STD_ALLOCATOR: (defined)\n";
+#else
+    std::cout << "BOOST_SP_USE_STD_ALLOCATOR: (not defined)\n";
+#endif
+
+    std::cout << n << " shared_ptr<int> allocations + deallocations:\n";
+
+    test<int>();
+    test<int>();
+    test<int>();
+
+    std::cout << n << " shared_ptr<X> allocations + deallocations:\n";
+
+    test<X>();
+    test<X>();
+    test<X>();
+}