diff --git a/include/boost/unordered/detail/implementation.hpp b/include/boost/unordered/detail/implementation.hpp
index 25f8ff83..60b831cb 100644
--- a/include/boost/unordered/detail/implementation.hpp
+++ b/include/boost/unordered/detail/implementation.hpp
@@ -3704,6 +3704,27 @@ struct table_impl : boost::unordered::detail::table<Types>
         }
     }
 
+    template <typename Key, typename M>
+    emplace_return insert_or_assign_impl(
+        BOOST_FWD_REF(Key) k, BOOST_FWD_REF(M) obj)
+    {
+        std::size_t key_hash = this->hash(k);
+        node_pointer pos = this->find_node(key_hash, k);
+
+        if (pos) {
+            pos->value().second = boost::forward<M>(obj);
+            return emplace_return(iterator(pos), false);
+        } else {
+            return emplace_return(
+                iterator(this->resize_and_add_node(
+                    boost::unordered::detail::func::construct_node_pair(
+                        this->node_alloc(), boost::forward<Key>(k),
+                        boost::forward<M>(obj)),
+                    key_hash)),
+                true);
+        }
+    }
+
     ////////////////////////////////////////////////////////////////////////
     // Insert range methods
     //
diff --git a/include/boost/unordered/unordered_map.hpp b/include/boost/unordered/unordered_map.hpp
index 3b842d54..bb3d5884 100644
--- a/include/boost/unordered/unordered_map.hpp
+++ b/include/boost/unordered/unordered_map.hpp
@@ -342,6 +342,37 @@ template <class K, class T, class H, class P, class A> class unordered_map
         return this->emplace_hint(hint, boost::move(x));
     }
 
+    template <class M>
+    std::pair<iterator, bool> insert_or_assign(
+        key_type const& k, BOOST_FWD_REF(M) obj)
+    {
+        return table_.insert_or_assign_impl(k, boost::forward<M>(obj));
+    }
+
+    template <class M>
+    iterator insert_or_assign(
+        const_iterator, key_type const& k, BOOST_FWD_REF(M) obj)
+    {
+        return table_.insert_or_assign_impl(k, boost::forward<M>(obj)).first;
+    }
+
+    template <class M>
+    std::pair<iterator, bool> insert_or_assign(
+        BOOST_RV_REF(key_type) k, BOOST_FWD_REF(M) obj)
+    {
+        return table_.insert_or_assign_impl(
+            boost::move(k), boost::forward<M>(obj));
+    }
+
+    template <class M>
+    iterator insert_or_assign(
+        const_iterator, BOOST_RV_REF(key_type) k, BOOST_FWD_REF(M) obj)
+    {
+        return table_
+            .insert_or_assign_impl(boost::move(k), boost::forward<M>(obj))
+            .first;
+    }
+
     template <class InputIt> void insert(InputIt, InputIt);
 
 #if !defined(BOOST_NO_CXX11_HDR_INITIALIZER_LIST)
diff --git a/test/unordered/compile_tests.hpp b/test/unordered/compile_tests.hpp
index 6c59860d..457b0238 100644
--- a/test/unordered/compile_tests.hpp
+++ b/test/unordered/compile_tests.hpp
@@ -301,13 +301,18 @@ template <class X, class T> void unordered_equivalent_test(X& r, T const& t)
 }
 
 template <class X, class Key, class T>
-void unordered_map_functions(X&, Key const& k, T const&)
+void unordered_map_functions(X&, Key const& k, T const& v)
 {
     typedef BOOST_DEDUCED_TYPENAME X::mapped_type mapped_type;
+    typedef BOOST_DEDUCED_TYPENAME X::iterator iterator;
 
     X a;
     test::check_return_type<mapped_type>::equals_ref(a[k]);
     test::check_return_type<mapped_type>::equals_ref(a.at(k));
+    test::check_return_type<std::pair<iterator, bool> >::equals(
+        a.insert_or_assign(k, v));
+    test::check_return_type<iterator>::equals(
+        a.insert_or_assign(a.begin(), k, v));
 
     X const b = a;
     test::check_return_type<mapped_type const>::equals_ref(b.at(k));
diff --git a/test/unordered/insert_tests.cpp b/test/unordered/insert_tests.cpp
index 1f477ade..86edfe24 100644
--- a/test/unordered/insert_tests.cpp
+++ b/test/unordered/insert_tests.cpp
@@ -505,6 +505,138 @@ template <class X> void map_tests(X*, test::random_generator generator)
     test::check_equivalent_keys(x);
 }
 
+template <class X> void map_tests2(X*, test::random_generator generator)
+{
+    typedef BOOST_DEDUCED_TYPENAME X::iterator iterator;
+    std::cerr << "insert_or_assign\n";
+
+    {
+        test::check_instances check_;
+
+        X x;
+        test::ordered<X> tracker = test::create_ordered(x);
+
+        test::random_values<X> v(1000, generator);
+        for (BOOST_DEDUCED_TYPENAME test::random_values<X>::iterator it =
+                 v.begin();
+             it != v.end(); ++it) {
+            BOOST_DEDUCED_TYPENAME X::size_type old_bucket_count =
+                x.bucket_count();
+            float b = x.max_load_factor();
+
+            std::pair<iterator, bool> r =
+                x.insert_or_assign(it->first, it->second);
+            BOOST_TEST(*r.first == *it);
+
+            tracker[it->first] = it->second;
+            tracker.compare_key(x, *it);
+
+            if (static_cast<double>(x.size()) <
+                b * static_cast<double>(old_bucket_count))
+                BOOST_TEST(x.bucket_count() == old_bucket_count);
+        }
+
+        tracker.compare(x);
+        test::check_equivalent_keys(x);
+    }
+
+    std::cerr << "insert_or_assign(begin)\n";
+
+    {
+        test::check_instances check_;
+
+        X x;
+        test::ordered<X> tracker = test::create_ordered(x);
+
+        test::random_values<X> v(1000, generator);
+        for (BOOST_DEDUCED_TYPENAME test::random_values<X>::iterator it =
+                 v.begin();
+             it != v.end(); ++it) {
+            BOOST_DEDUCED_TYPENAME X::size_type old_bucket_count =
+                x.bucket_count();
+            float b = x.max_load_factor();
+
+            iterator r = x.insert_or_assign(x.begin(), it->first, it->second);
+            BOOST_TEST(*r == *it);
+
+            tracker[it->first] = it->second;
+            tracker.compare_key(x, *it);
+
+            if (static_cast<double>(x.size()) <
+                b * static_cast<double>(old_bucket_count))
+                BOOST_TEST(x.bucket_count() == old_bucket_count);
+        }
+
+        tracker.compare(x);
+        test::check_equivalent_keys(x);
+    }
+
+    std::cerr << "insert_or_assign(end)\n";
+
+    {
+        test::check_instances check_;
+
+        X x;
+        test::ordered<X> tracker = test::create_ordered(x);
+
+        test::random_values<X> v(1000, generator);
+        for (BOOST_DEDUCED_TYPENAME test::random_values<X>::iterator it =
+                 v.begin();
+             it != v.end(); ++it) {
+            BOOST_DEDUCED_TYPENAME X::size_type old_bucket_count =
+                x.bucket_count();
+            float b = x.max_load_factor();
+
+            iterator r = x.insert_or_assign(x.end(), it->first, it->second);
+            BOOST_TEST(*r == *it);
+
+            tracker[it->first] = it->second;
+            tracker.compare_key(x, *it);
+
+            if (static_cast<double>(x.size()) <
+                b * static_cast<double>(old_bucket_count))
+                BOOST_TEST(x.bucket_count() == old_bucket_count);
+        }
+
+        tracker.compare(x);
+        test::check_equivalent_keys(x);
+    }
+
+    std::cerr << "insert_or_assign(last)\n";
+
+    {
+        test::check_instances check_;
+
+        X x;
+        test::ordered<X> tracker = test::create_ordered(x);
+        iterator last = x.begin();
+
+        test::random_values<X> v(1000, generator);
+        for (BOOST_DEDUCED_TYPENAME test::random_values<X>::iterator it =
+                 v.begin();
+             it != v.end(); ++it) {
+            BOOST_DEDUCED_TYPENAME X::size_type old_bucket_count =
+                x.bucket_count();
+            float b = x.max_load_factor();
+
+            iterator r = x.insert_or_assign(last, it->first, it->second);
+            BOOST_TEST(*r == *it);
+
+            tracker[it->first] = it->second;
+            tracker.compare_key(x, *it);
+
+            if (static_cast<double>(x.size()) <
+                b * static_cast<double>(old_bucket_count))
+                BOOST_TEST(x.bucket_count() == old_bucket_count);
+
+            last = r;
+        }
+
+        tracker.compare(x);
+        test::check_equivalent_keys(x);
+    }
+}
+
 // Some tests for when the range's value type doesn't match the container's
 // value type.
 
@@ -600,6 +732,9 @@ UNORDERED_TEST(default_emplace_tests,
 UNORDERED_TEST(map_tests,
     ((test_map))((default_generator)(generate_collisions)(limited_range)))
 
+UNORDERED_TEST(
+    map_tests2, ((test_map))((default_generator)(generate_collisions)))
+
 UNORDERED_TEST(map_insert_range_test1,
     ((test_multimap_std_alloc)(test_map)(test_multimap))(
                    (default_generator)(generate_collisions)(limited_range)))