diff --git a/include/boost/unordered/concurrent_flat_map.hpp b/include/boost/unordered/concurrent_flat_map.hpp
index 6f5c9ff3..a20a6776 100644
--- a/include/boost/unordered/concurrent_flat_map.hpp
+++ b/include/boost/unordered/concurrent_flat_map.hpp
@@ -16,6 +16,7 @@
 #define BOOST_UNORDERED_CONCURRENT_FLAT_MAP_HPP
 
 #include <boost/unordered/detail/foa/concurrent_table.hpp>
+#include <boost/unordered/detail/type_traits.hpp>
 
 #include <boost/container_hash/hash.hpp>
 #include <boost/core/allocator_access.hpp>
@@ -163,6 +164,17 @@ namespace boost {
           std::forward<M>(obj));
       }
 
+      template <class K, class M>
+      typename std::enable_if<
+        detail::are_transparent<K, hasher, key_equal>::value, bool>::type
+      insert_or_assign(K&& k, M&& obj)
+      {
+        return table_.try_emplace_or_visit(
+          std::forward<K>(k),
+          [&](value_type& m) { m.second = std::forward<M>(obj); },
+          std::forward<M>(obj));
+      }
+
       /// Hash Policy
       ///
       void rehash(size_type n) { table_.rehash(n); }
diff --git a/test/cfoa/insert_tests.cpp b/test/cfoa/insert_tests.cpp
index 96ac926d..c860c2ff 100644
--- a/test/cfoa/insert_tests.cpp
+++ b/test/cfoa/insert_tests.cpp
@@ -8,6 +8,7 @@
 #include <boost/unordered/concurrent_flat_map.hpp>
 
 #include <boost/container_hash/hash.hpp>
+#include <boost/core/ignore_unused.hpp>
 #include <boost/core/span.hpp>
 #include <boost/unordered/unordered_flat_map.hpp>
 
@@ -19,6 +20,26 @@
 
 constexpr std::size_t const num_threads = 16;
 
+struct transparent_hash
+{
+  using is_transparent = void;
+
+  template <class T> std::size_t operator()(T const& t) const noexcept
+  {
+    return boost::hash<T>()(t);
+  }
+};
+
+struct transparent_key_equal
+{
+  using is_transparent = void;
+
+  template <class T, class U> bool operator()(T const& lhs, U const& rhs) const
+  {
+    return lhs == rhs;
+  }
+};
+
 struct raii
 {
   static std::atomic_int default_constructor;
@@ -70,6 +91,25 @@ struct raii
     return !(lhs == rhs);
   }
 
+  friend bool operator==(raii const& lhs, int const x)
+  {
+    return lhs.x_ == x;
+  }
+  friend bool operator!=(raii const& lhs, int const x)
+  {
+    return !(lhs.x_ == x);
+  }
+
+  friend bool operator==(int const x, raii const& rhs)
+  {
+    return rhs.x_ == x;
+  }
+
+  friend bool operator!=(int const x, raii const& rhs)
+  {
+    return !(rhs.x_ == x);
+  }
+
   friend std::ostream& operator<<(std::ostream& os, raii const& rhs)
   {
     os << "{ x_: " << rhs.x_ << " }";
@@ -300,6 +340,7 @@ namespace {
         }
       });
 
+      BOOST_TEST_EQ(raii::default_constructor, 0);
       BOOST_TEST_EQ(raii::copy_constructor, 2 * x.size());
       // don't check move construction count here because of rehashing
       BOOST_TEST_GT(raii::move_constructor, 0);
@@ -318,6 +359,7 @@ namespace {
         }
       });
 
+      BOOST_TEST_EQ(raii::default_constructor, 0);
       BOOST_TEST_EQ(raii::copy_constructor, x.size());
       BOOST_TEST_GT(raii::move_constructor, x.size()); // rehashing
       BOOST_TEST_EQ(raii::copy_assignment, 0);
@@ -335,6 +377,7 @@ namespace {
         }
       });
 
+      BOOST_TEST_EQ(raii::default_constructor, 0);
       BOOST_TEST_EQ(raii::copy_constructor, x.size());
       BOOST_TEST_GT(raii::move_constructor, x.size()); // rehashing
       BOOST_TEST_EQ(raii::copy_assignment, values.size() - x.size());
@@ -352,11 +395,62 @@ namespace {
         }
       });
 
+      BOOST_TEST_EQ(raii::default_constructor, 0);
       BOOST_TEST_EQ(raii::copy_assignment, 0);
       BOOST_TEST_EQ(raii::move_assignment, values.size() - x.size());
     }
   } rvalue_insert_or_assign_move_assign;
 
+  struct transparent_insert_or_assign_copy_assign_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      using is_transparent =
+        typename boost::make_void<typename X::hasher::is_transparent,
+          typename X::key_equal::is_transparent>::type;
+
+      boost::ignore_unused<is_transparent>();
+
+      BOOST_TEST_EQ(raii::default_constructor, 0);
+
+      thread_runner(values, [&x](boost::span<T> s) {
+        for (auto& r : s) {
+          x.insert_or_assign(r.first.x_, r.second);
+        }
+      });
+
+      BOOST_TEST_EQ(raii::default_constructor, x.size());
+      BOOST_TEST_EQ(raii::copy_constructor, x.size());
+      BOOST_TEST_GT(raii::move_constructor, x.size()); // rehashing
+      BOOST_TEST_EQ(raii::copy_assignment, values.size() - x.size());
+      BOOST_TEST_EQ(raii::move_assignment, 0);
+    }
+  } transparent_insert_or_assign_copy_assign;
+
+  struct transparent_insert_or_assign_move_assign_type
+  {
+    template <class T, class X> void operator()(std::vector<T>& values, X& x)
+    {
+      using is_transparent =
+        typename boost::make_void<typename X::hasher::is_transparent,
+          typename X::key_equal::is_transparent>::type;
+
+      boost::ignore_unused<is_transparent>();
+
+      thread_runner(values, [&x](boost::span<T> s) {
+        for (auto& r : s) {
+          x.insert_or_assign(r.first.x_, std::move(r.second));
+        }
+      });
+
+      BOOST_TEST_EQ(raii::default_constructor, x.size());
+      BOOST_TEST_EQ(raii::copy_constructor, 0);
+      BOOST_TEST_GT(raii::move_constructor, 2 * x.size()); // rehashing
+      BOOST_TEST_EQ(raii::copy_assignment, 0);
+      BOOST_TEST_EQ(raii::move_assignment, values.size() - x.size());
+    }
+  } transparent_insert_or_assign_move_assign;
+
   template <class X, class G, class F>
   void insert(X*, G gen, F inserter, test::random_generator rg)
   {
@@ -454,6 +548,8 @@ namespace {
   }
 
   boost::unordered::concurrent_flat_map<raii, raii>* map;
+  boost::unordered::concurrent_flat_map<raii, raii, transparent_hash,
+    transparent_key_equal>* transparent_map;
 
 } // namespace
 
@@ -488,6 +584,13 @@ UNORDERED_TEST(
   ((lvalue_insert_or_assign_copy_assign)(lvalue_insert_or_assign_move_assign)
    (rvalue_insert_or_assign_copy_assign)(rvalue_insert_or_assign_move_assign))
   ((default_generator)(sequential)(limited_range)))
+
+UNORDERED_TEST(
+  insert,
+  ((transparent_map))
+  ((init_type_generator))
+  ((transparent_insert_or_assign_copy_assign)(transparent_insert_or_assign_move_assign))
+  ((default_generator)(sequential)(limited_range)))
 // clang-format on
 
 RUN_TESTS()