diff --git a/stl/inc/xutility b/stl/inc/xutility
index 8ba56f690c0..1de1ee9c336 100644
--- a/stl/inc/xutility
+++ b/stl/inc/xutility
@@ -2377,6 +2377,7 @@ private:
     }
 
 public:
+    using iterator_type    = _Iter;
     using iterator_concept = decltype(_Get_iter_concept());
     using value_type       = iter_value_t<_Iter>;
     using difference_type  = iter_difference_t<_Iter>;
diff --git a/tests/std/tests/P2278R4_basic_const_iterator/test.cpp b/tests/std/tests/P2278R4_basic_const_iterator/test.cpp
index 028631d7ddd..aa861d14580 100644
--- a/tests/std/tests/P2278R4_basic_const_iterator/test.cpp
+++ b/tests/std/tests/P2278R4_basic_const_iterator/test.cpp
@@ -38,6 +38,7 @@ constexpr void test_one(It iter) {
     static_assert(contiguous_iterator<ConstIt> == contiguous_iterator<It>);
 
     // Validate nested types
+    static_assert(same_as<typename ConstIt::iterator_type, It>);
     static_assert(same_as<typename ConstIt::value_type, iter_value_t<It>>);
     static_assert(same_as<typename ConstIt::difference_type, iter_difference_t<It>>);
     if constexpr (forward_iterator<It>) {