diff --git a/stl/inc/type_traits b/stl/inc/type_traits
index 103cb1fa5c9..463db6fd760 100644
--- a/stl/inc/type_traits
+++ b/stl/inc/type_traits
@@ -1554,7 +1554,8 @@ struct _Invoker1;
 
 template <class _Callable, class _Ty1, class _Removed_cvref>
 struct _Invoker1<_Callable, _Ty1, _Removed_cvref, true, false>
-    : conditional_t<is_base_of_v<typename _Is_memfunptr<_Removed_cvref>::_Class_type, remove_reference_t<_Ty1>>,
+    : conditional_t<is_same_v<typename _Is_memfunptr<_Removed_cvref>::_Class_type, _Remove_cvref_t<_Ty1>>
+                        || is_base_of_v<typename _Is_memfunptr<_Removed_cvref>::_Class_type, _Remove_cvref_t<_Ty1>>,
           _Invoker_pmf_object,
           conditional_t<_Is_specialization_v<_Remove_cvref_t<_Ty1>, reference_wrapper>, _Invoker_pmf_refwrap,
               _Invoker_pmf_pointer>> {}; // pointer to member function
@@ -1562,7 +1563,8 @@ struct _Invoker1<_Callable, _Ty1, _Removed_cvref, true, false>
 template <class _Callable, class _Ty1, class _Removed_cvref>
 struct _Invoker1<_Callable, _Ty1, _Removed_cvref, false, true>
     : conditional_t<
-          is_base_of_v<typename _Is_member_object_pointer<_Removed_cvref>::_Class_type, remove_reference_t<_Ty1>>,
+          is_same_v<typename _Is_member_object_pointer<_Removed_cvref>::_Class_type, _Remove_cvref_t<_Ty1>>
+              || is_base_of_v<typename _Is_member_object_pointer<_Removed_cvref>::_Class_type, _Remove_cvref_t<_Ty1>>,
           _Invoker_pmd_object,
           conditional_t<_Is_specialization_v<_Remove_cvref_t<_Ty1>, reference_wrapper>, _Invoker_pmd_refwrap,
               _Invoker_pmd_pointer>> {}; // pointer to member data
diff --git a/tests/std/tests/P2136R3_invoke_r/test.cpp b/tests/std/tests/P2136R3_invoke_r/test.cpp
index f8d7bac3192..e8beb0e9965 100644
--- a/tests/std/tests/P2136R3_invoke_r/test.cpp
+++ b/tests/std/tests/P2136R3_invoke_r/test.cpp
@@ -109,6 +109,25 @@ constexpr bool test_invoke_r() {
     return true;
 }
 
+// LWG-3655: The INVOKE operation and union types
+union Union {
+    int x;
+};
+static_assert(is_invocable_v<int Union::*, Union>);
+static_assert(is_invocable_v<int Union::*, Union&>);
+static_assert(is_invocable_v<int Union::*, const Union>);
+static_assert(is_invocable_v<int Union::*, const Union&>);
+
+static_assert(is_invocable_v<void (Union::*)(), Union>);
+static_assert(is_invocable_v<void (Union::*)(), Union&>);
+static_assert(!is_invocable_v<void (Union::*)(), const Union>);
+static_assert(!is_invocable_v<void (Union::*)(), const Union&>);
+
+static_assert(is_invocable_v<void (Union::*)() const, Union>);
+static_assert(is_invocable_v<void (Union::*)() const, Union&>);
+static_assert(is_invocable_v<void (Union::*)() const, const Union>);
+static_assert(is_invocable_v<void (Union::*)() const, const Union&>);
+
 int main() {
     test_invoke_r();
     STATIC_ASSERT(test_invoke_r());