diff --git a/libstdc++-v3/include/debug/safe_iterator.h b/libstdc++-v3/include/debug/safe_iterator.h
index f9068eaf8d6..e7c96d1af27 100644
--- a/libstdc++-v3/include/debug/safe_iterator.h
+++ b/libstdc++-v3/include/debug/safe_iterator.h
@@ -129,14 +129,6 @@ namespace __gnu_debug
 	typename _Sequence::_Base::iterator,
 	typename _Sequence::_Base::const_iterator>::__type _OtherIterator;
 
-      struct _Attach_single
-      { };
-
-      _Safe_iterator(_Iterator __i, _Safe_sequence_base* __seq, _Attach_single)
-      _GLIBCXX_NOEXCEPT
-      : _Iter_base(__i)
-      { _M_attach_single(__seq); }
-
     public:
       typedef _Iterator					iterator_type;
       typedef typename _Traits::iterator_category	iterator_category;
@@ -347,8 +339,13 @@ namespace __gnu_debug
 	_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
 			      _M_message(__msg_bad_inc)
 			      ._M_iterator(*this, "this"));
-	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
-	return _Safe_iterator(base()++, this->_M_sequence, _Attach_single());
+	_Iter_base __cur;
+	{
+	  __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
+	  __cur = base()++;
+	}
+
+	return _Safe_iterator(__cur, this->_M_sequence);
       }
 
       // ------ Utilities ------
@@ -520,12 +517,6 @@ namespace __gnu_debug
 
     protected:
       typedef typename _Safe_base::_OtherIterator _OtherIterator;
-      typedef typename _Safe_base::_Attach_single _Attach_single;
-
-      _Safe_iterator(_Iterator __i, _Safe_sequence_base* __seq, _Attach_single)
-      _GLIBCXX_NOEXCEPT
-      : _Safe_base(__i, __seq, _Attach_single())
-      { }
 
     public:
       /// @post the iterator is singular and unattached
@@ -609,9 +600,13 @@ namespace __gnu_debug
 	_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
 			      _M_message(__msg_bad_inc)
 			      ._M_iterator(*this, "this"));
-	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
-	return _Safe_iterator(this->base()++, this->_M_sequence,
-			      _Attach_single());
+	_Iter_base __cur;
+	{
+	  __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
+	  __cur = this->base()++;
+	}
+
+	return _Safe_iterator(__cur, this->_M_sequence);
       }
 
       // ------ Bidirectional iterator requirements ------
@@ -640,9 +635,13 @@ namespace __gnu_debug
 	_GLIBCXX_DEBUG_VERIFY(this->_M_decrementable(),
 			      _M_message(__msg_bad_dec)
 			      ._M_iterator(*this, "this"));
-	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
-	return _Safe_iterator(this->base()--, this->_M_sequence,
-			      _Attach_single());
+	_Iter_base __cur;
+	{
+	  __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
+	  __cur = this->base()--;
+	}
+
+	return _Safe_iterator(__cur, this->_M_sequence);
       }
 
       // ------ Utilities ------
@@ -666,13 +665,6 @@ namespace __gnu_debug
       typedef _Safe_iterator<_OtherIterator, _Sequence,
 			     std::random_access_iterator_tag> _OtherSelf;
 
-      typedef typename _Safe_base::_Attach_single _Attach_single;
-
-      _Safe_iterator(_Iterator __i, _Safe_sequence_base* __seq, _Attach_single)
-      _GLIBCXX_NOEXCEPT
-      : _Safe_base(__i, __seq, _Attach_single())
-      { }
-
     public:
       typedef typename _Safe_base::difference_type	difference_type;
       typedef typename _Safe_base::reference		reference;
@@ -761,9 +753,16 @@ namespace __gnu_debug
       _Safe_iterator
       operator++(int) _GLIBCXX_NOEXCEPT
       {
-	_Safe_iterator __ret = *this;
-	++*this;
-	return __ret;
+	_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
+			      _M_message(__msg_bad_inc)
+			      ._M_iterator(*this, "this"));
+	_Iter_base __cur;
+	{
+	  __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
+	  __cur = this->base()++;
+	}
+
+	return _Safe_iterator(__cur, this->_M_sequence);
       }
 
       // ------ Bidirectional iterator requirements ------
@@ -785,9 +784,16 @@ namespace __gnu_debug
       _Safe_iterator
       operator--(int) _GLIBCXX_NOEXCEPT
       {
-	_Safe_iterator __ret = *this;
-	--*this;
-	return __ret;
+	_GLIBCXX_DEBUG_VERIFY(this->_M_decrementable(),
+			      _M_message(__msg_bad_dec)
+			      ._M_iterator(*this, "this"));
+	_Iter_base __cur;
+	{
+	  __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
+	  __cur = this->base()--;
+	}
+
+	return _Safe_iterator(__cur, this->_M_sequence);
       }
 
       // ------ Random access iterator requirements ------
diff --git a/libstdc++-v3/include/debug/safe_local_iterator.h b/libstdc++-v3/include/debug/safe_local_iterator.h
index 6e3c4eb1505..3c525652ea1 100644
--- a/libstdc++-v3/include/debug/safe_local_iterator.h
+++ b/libstdc++-v3/include/debug/safe_local_iterator.h
@@ -84,14 +84,6 @@ namespace __gnu_debug
       typedef _Safe_local_iterator _Self;
       typedef _Safe_local_iterator<_OtherIterator, _Sequence> _OtherSelf;
 
-      struct _Attach_single
-      { };
-
-      _Safe_local_iterator(_Iterator __i, _Safe_sequence_base* __cont,
-			   _Attach_single) noexcept
-      : _Iter_base(__i)
-      { _M_attach_single(__cont); }
-
     public:
       typedef _Iterator					iterator_type;
       typedef typename _Traits::iterator_category	iterator_category;
@@ -290,9 +282,13 @@ namespace __gnu_debug
 	_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
 			      _M_message(__msg_bad_inc)
 			      ._M_iterator(*this, "this"));
-	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
-	return _Safe_local_iterator(base()++, this->_M_sequence,
-				    _Attach_single());
+	_Iter_base __cur;
+	{
+	  __gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
+	  __cur = base()++;
+	}
+
+	return { __cur, this->_M_sequence };
       }
 
       // ------ Utilities ------
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_map/debug/invalid_local_iterator_post_increment_neg.cc b/libstdc++-v3/testsuite/23_containers/unordered_map/debug/invalid_local_iterator_post_increment_neg.cc
new file mode 100644
index 00000000000..74005c3ec69
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_map/debug/invalid_local_iterator_post_increment_neg.cc
@@ -0,0 +1,16 @@
+// { dg-do run { target c++11 xfail *-*-* } }
+// { dg-require-debug-mode "" }
+
+#include <unordered_map>
+#include <debug/unordered_checks.h>
+
+void test01()
+{
+  __gnu_test::invalid_local_iterator_post_increment<std::unordered_map<int, int>>();
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_map/debug/invalid_local_iterator_pre_increment_neg.cc b/libstdc++-v3/testsuite/23_containers/unordered_map/debug/invalid_local_iterator_pre_increment_neg.cc
new file mode 100644
index 00000000000..016cd1c6947
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_map/debug/invalid_local_iterator_pre_increment_neg.cc
@@ -0,0 +1,16 @@
+// { dg-do run { target c++11 xfail *-*-* } }
+// { dg-require-debug-mode "" }
+
+#include <unordered_map>
+#include <debug/unordered_checks.h>
+
+void test01()
+{
+  __gnu_test::invalid_local_iterator_pre_increment<std::unordered_map<int, int>>();
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/util/debug/unordered_checks.h b/libstdc++-v3/testsuite/util/debug/unordered_checks.h
index 655f16f199f..971fe68396b 100644
--- a/libstdc++-v3/testsuite/util/debug/unordered_checks.h
+++ b/libstdc++-v3/testsuite/util/debug/unordered_checks.h
@@ -125,6 +125,38 @@ namespace __gnu_test
       VERIFY( *it == val );
     }
 
+  template<typename _Tp>
+    void invalid_local_iterator_pre_increment()
+    {
+      typedef _Tp cont_type;
+      typedef typename cont_type::value_type cont_val_type;
+      typedef typename CopyableValueType<cont_val_type>::value_type val_type;
+      generate_unique<val_type> gu;
+
+      cont_type c;
+      for (size_t i = 0; i != 5; ++i)
+	c.insert(gu.build());
+
+      for (auto lit = c.begin(0); ;)
+	++lit;
+    }
+
+  template<typename _Tp>
+    void invalid_local_iterator_post_increment()
+    {
+      typedef _Tp cont_type;
+      typedef typename cont_type::value_type cont_val_type;
+      typedef typename CopyableValueType<cont_val_type>::value_type val_type;
+      generate_unique<val_type> gu;
+
+      cont_type c;
+      for (size_t i = 0; i != 5; ++i)
+	c.insert(gu.build());
+
+      for (auto it = c.begin(0); ;)
+	it++;
+    }
+
   template<typename _Tp>
     void invalid_local_iterator_compare()
     {