diff --git a/include/boost/unordered_map.hpp b/include/boost/unordered_map.hpp
index 2d26fc63..009e7f9d 100644
--- a/include/boost/unordered_map.hpp
+++ b/include/boost/unordered_map.hpp
@@ -172,6 +172,16 @@ namespace boost
             return const_iterator(base.end());
         }
 
+        const_iterator cbegin() const
+        {
+            return const_iterator(base.begin());
+        }
+
+        const_iterator cend() const
+        {
+            return const_iterator(base.end());
+        }
+
         // modifiers
 
         std::pair<iterator, bool> insert(const value_type& obj)
@@ -321,6 +331,18 @@ namespace boost
             return const_local_iterator(base.end(n));
         }
 
+#if defined(BOOST_UNORDERED_LOCAL_CBEGIN)
+        const_local_iterator cbegin(size_type n) const
+        {
+            return const_local_iterator(base.begin(n));
+        }
+        
+        const_local_iterator cend(size_type n) const
+        {
+            return const_local_iterator(base.end(n));
+        }
+#endif
+
         // hash policy
 
         float load_factor() const
@@ -475,6 +497,16 @@ namespace boost
             return const_iterator(base.end());
         }
 
+        const_iterator cbegin() const
+        {
+            return const_iterator(base.begin());
+        }
+
+        const_iterator cend() const
+        {
+            return const_iterator(base.end());
+        }
+
         // modifiers
 
         iterator insert(const value_type& obj)
@@ -618,6 +650,18 @@ namespace boost
             return const_local_iterator(base.end(n));
         }
 
+#if defined(BOOST_UNORDERED_LOCAL_CBEGIN)
+        const_local_iterator cbegin(size_type n) const
+        {
+            return const_local_iterator(base.begin(n));
+        }
+
+        const_local_iterator cend(size_type n) const
+        {
+            return const_local_iterator(base.end(n));
+        }
+#endif
+
         // hash policy
 
         float load_factor() const
diff --git a/include/boost/unordered_set.hpp b/include/boost/unordered_set.hpp
index 75d16031..ee5a9b6c 100644
--- a/include/boost/unordered_set.hpp
+++ b/include/boost/unordered_set.hpp
@@ -144,6 +144,16 @@ namespace boost
             return const_iterator(base.end());
         }
 
+        const_iterator cbegin() const
+        {
+            return const_iterator(base.begin());
+        }
+
+        const_iterator cend() const
+        {
+            return const_iterator(base.end());
+        }
+
         // modifiers
 
         std::pair<iterator, bool> insert(const value_type& obj)
@@ -261,6 +271,17 @@ namespace boost
             return const_local_iterator(base.end(n));
         }
 
+#if defined(BOOST_UNORDERED_LOCAL_CBEGIN)
+        const_local_iterator cbegin(size_type n) const
+        {
+            return const_local_iterator(base.begin(n));
+        }
+
+        const_local_iterator cend(size_type n) const
+        {
+            return const_local_iterator(base.end(n));
+        }
+#endif
 
         // hash policy
 
@@ -413,6 +434,16 @@ namespace boost
             return const_iterator(base.end());
         }
 
+        const_iterator cbegin() const
+        {
+            return const_iterator(base.begin());
+        }
+
+        const_iterator cend() const
+        {
+            return const_iterator(base.end());
+        }
+
         // modifiers
 
         iterator insert(const value_type& obj)
@@ -529,6 +560,18 @@ namespace boost
             return const_local_iterator(base.end(n));
         }
 
+#if defined(BOOST_UNORDERED_LOCAL_CBEGIN)
+        const_local_iterator cbegin(size_type n) const
+        {
+            return const_local_iterator(base.begin(n));
+        }
+
+        const_local_iterator cend(size_type n) const
+        {
+            return const_local_iterator(base.end(n));
+        }
+#endif
+
         // hash policy
 
         float load_factor() const