diff --git a/include/boost/smart_ptr/make_shared.hpp b/include/boost/smart_ptr/make_shared.hpp
index 58e38d2..25b9cf0 100644
--- a/include/boost/smart_ptr/make_shared.hpp
+++ b/include/boost/smart_ptr/make_shared.hpp
@@ -60,6 +60,11 @@ public:
     {
     }
 
+    // optimization: do not copy storage_
+    sp_ms_deleter( sp_ms_deleter const & ): initialized_( false )
+    {
+    }
+
     ~sp_ms_deleter()
     {
         destroy();