diff --git a/include/boost/archive/iterators/mb_from_wchar.hpp b/include/boost/archive/iterators/mb_from_wchar.hpp
index 52979565..d5110de2 100644
--- a/include/boost/archive/iterators/mb_from_wchar.hpp
+++ b/include/boost/archive/iterators/mb_from_wchar.hpp
@@ -116,6 +116,7 @@ public:
     template<class T>
     mb_from_wchar(T start) :
         super_t(Base(static_cast< T >(start))),
+        m_mbs(std::mbstate_t()),
         m_bend(0),
         m_bnext(0),
         m_full(false)
diff --git a/include/boost/archive/iterators/wchar_from_mb.hpp b/include/boost/archive/iterators/wchar_from_mb.hpp
index 029e96be..dbeb8f69 100644
--- a/include/boost/archive/iterators/wchar_from_mb.hpp
+++ b/include/boost/archive/iterators/wchar_from_mb.hpp
@@ -124,8 +124,10 @@ public:
     // make composible buy using templated constructor
     template<class T>
     wchar_from_mb(T start) : 
-        super_t(Base(static_cast< T >(start)))
+        super_t(Base(static_cast< T >(start))),
+        m_mbs(std::mbstate_t())
     {
+        BOOST_ASSERT(std::mbsinit(&m_mbs));
         drain();
     }
     // copy ctor
diff --git a/test/test_iterators.cpp b/test/test_iterators.cpp
index a45a3e6c..ad63eb37 100644
--- a/test/test_iterators.cpp
+++ b/test/test_iterators.cpp
@@ -66,7 +66,6 @@ void test_mb_from_wchar(const char * a, const wchar_t *la, const unsigned int si
 void test_roundtrip(const wchar_t * la){
     std::size_t s = std::wcslen(la);
     std::vector<char> a;
-    std::vector<wchar_t> la2;
     {
         typedef boost::archive::iterators::mb_from_wchar<const wchar_t *> translator;
         std::copy(
@@ -74,8 +73,10 @@ void test_roundtrip(const wchar_t * la){
             translator(la + s),
             std::back_inserter(a)
         );
+        a.push_back((char)0);
     }
     BOOST_CHECK(a.size() > 0);
+    std::vector<wchar_t> la2;
     {
         typedef boost::archive::iterators::wchar_from_mb<std::vector<char>::const_iterator> translator;
         std::copy(
@@ -83,8 +84,9 @@ void test_roundtrip(const wchar_t * la){
             translator(a.end()),
             std::back_inserter(la2)
         );
+        la2.push_back((wchar_t)0);
     }
-    BOOST_CHECK(la2.size() == s);
+    BOOST_CHECK(la2.size() == s + 1);
     BOOST_CHECK(std::equal(la, la + s, la2.begin()));
 }
 #endif
@@ -253,5 +255,3 @@ test_main(int /* argc */, char* /* argv */ [] )
 
     return EXIT_SUCCESS;
 }
-
-