diff --git a/include/boost/openmethod/interop/boost_any.hpp b/include/boost/openmethod/interop/boost_any.hpp
index 8a1a85cf..320c32a1 100644
--- a/include/boost/openmethod/interop/boost_any.hpp
+++ b/include/boost/openmethod/interop/boost_any.hpp
@@ -20,17 +20,18 @@ namespace boost::openmethod {
 
 namespace detail {
 
-template<class Registry>
-struct validate_method_parameter<virtual_<const boost::any&>, Registry, void> :
+template<class ParamRegistry, class Registry>
+struct validate_method_parameter<
+    virtual_<const boost::any&, ParamRegistry>, Registry, void> :
     std::true_type {};
 
-template<class Registry>
-struct validate_method_parameter<virtual_<boost::any&>, Registry, void> :
-    std::true_type {};
+template<class ParamRegistry, class Registry>
+struct validate_method_parameter<
+    virtual_<boost::any&, ParamRegistry>, Registry, void> : std::true_type {};
 
-template<class Registry>
-struct validate_method_parameter<virtual_<boost::any&&>, Registry, void> :
-    std::true_type {};
+template<class ParamRegistry, class Registry>
+struct validate_method_parameter<
+    virtual_<boost::any&&, ParamRegistry>, Registry, void> : std::true_type {};
 
 // `boost::any::type()` yields a `std::type_info`, which is a valid `type_id`
 // only for an rtti policy that identifies classes by `&typeid(T)`. Under any
diff --git a/include/boost/openmethod/interop/boost_type_erasure.hpp b/include/boost/openmethod/interop/boost_type_erasure.hpp
index fea69760..a6f53f9b 100644
--- a/include/boost/openmethod/interop/boost_type_erasure.hpp
+++ b/include/boost/openmethod/interop/boost_type_erasure.hpp
@@ -94,35 +94,36 @@ constexpr bool te_pass_through =
 // placeholder of the parameter, so methods and overriders agree on a
 // single registered root per Concept.
 
-template<class C, typename T, class Registry>
+template<class C, typename T, class ParamRegistry, class Registry>
 struct validate_method_parameter<
-    virtual_<const boost::type_erasure::any<C, T>&>, Registry, void> :
-    std::true_type {};
+    virtual_<const boost::type_erasure::any<C, T>&, ParamRegistry>, Registry,
+    void> : std::true_type {};
 
-template<class C, typename T, class Registry>
+template<class C, typename T, class ParamRegistry, class Registry>
 struct validate_method_parameter<
-    virtual_<boost::type_erasure::any<C, T>&>, Registry, void> :
+    virtual_<boost::type_erasure::any<C, T>&, ParamRegistry>, Registry, void> :
     std::true_type {};
 
-template<class C, typename T, class Registry>
+template<class C, typename T, class ParamRegistry, class Registry>
 struct validate_method_parameter<
-    virtual_<boost::type_erasure::any<C, T>&&>, Registry, void> :
+    virtual_<boost::type_erasure::any<C, T>&&, ParamRegistry>, Registry, void> :
     std::true_type {};
 
-template<class C, typename T, class Registry>
+template<class C, typename T, class ParamRegistry, class Registry>
 struct validate_method_parameter<
-    virtual_<boost::type_erasure::any<C, T&>>, Registry, void> :
+    virtual_<boost::type_erasure::any<C, T&>, ParamRegistry>, Registry, void> :
     std::true_type {};
 
-template<class C, typename T, class Registry>
+template<class C, typename T, class ParamRegistry, class Registry>
 struct validate_method_parameter<
-    virtual_<boost::type_erasure::any<C, const T&>>, Registry, void> :
-    std::true_type {};
+    virtual_<boost::type_erasure::any<C, const T&>, ParamRegistry>, Registry,
+    void> : std::true_type {};
 
-template<class C, class Registry>
+template<class C, class ParamRegistry, class Registry>
 struct validate_method_parameter<
-    virtual_<boost::type_erasure::any<C, boost::type_erasure::_self>>, Registry,
-    void> : std::false_type {
+    virtual_<
+        boost::type_erasure::any<C, boost::type_erasure::_self>, ParamRegistry>,
+    Registry, void> : std::false_type {
     static_assert(
         false_t<C>, "an owning type_erasure::any must be passed by reference");
 };
diff --git a/include/boost/openmethod/interop/std_any.hpp b/include/boost/openmethod/interop/std_any.hpp
index 315268c0..e5ee6247 100644
--- a/include/boost/openmethod/interop/std_any.hpp
+++ b/include/boost/openmethod/interop/std_any.hpp
@@ -20,17 +20,18 @@ namespace boost::openmethod {
 
 namespace detail {
 
-template<class Registry>
-struct validate_method_parameter<virtual_<const std::any&>, Registry, void> :
+template<class ParamRegistry, class Registry>
+struct validate_method_parameter<
+    virtual_<const std::any&, ParamRegistry>, Registry, void> :
     std::true_type {};
 
-template<class Registry>
-struct validate_method_parameter<virtual_<std::any&>, Registry, void> :
-    std::true_type {};
+template<class ParamRegistry, class Registry>
+struct validate_method_parameter<
+    virtual_<std::any&, ParamRegistry>, Registry, void> : std::true_type {};
 
-template<class Registry>
-struct validate_method_parameter<virtual_<std::any&&>, Registry, void> :
-    std::true_type {};
+template<class ParamRegistry, class Registry>
+struct validate_method_parameter<
+    virtual_<std::any&&, ParamRegistry>, Registry, void> : std::true_type {};
 
 // `std::any::type()` yields a `std::type_info`, which is a valid `type_id`
 // only for an rtti policy that identifies classes by `&typeid(T)`. Under any
diff --git a/test/test_dispatch_boost_any.cpp b/test/test_dispatch_boost_any.cpp
index d2cbfcda..6f0d40de 100644
--- a/test/test_dispatch_boost_any.cpp
+++ b/test/test_dispatch_boost_any.cpp
@@ -32,6 +32,18 @@ static_assert(detail::has_vptr<
               virtual_traits<const boost::any&, default_registry>,
               const boost::any&>);
 
+// A registry spelled on the parameter names the same parameter as the default
+// one, in each of the three forms.
+static_assert(detail::validate_method_parameter<
+              virtual_<const boost::any&, default_registry>, default_registry,
+              void>::value);
+static_assert(detail::validate_method_parameter<
+              virtual_<boost::any&, default_registry>, default_registry,
+              void>::value);
+static_assert(detail::validate_method_parameter<
+              virtual_<boost::any&&, default_registry>, default_registry,
+              void>::value);
+
 MAKE_CLASSES();
 
 BOOST_OPENMETHOD(name, (virtual_<const boost::any&>), std::string);
diff --git a/test/test_dispatch_std_any.cpp b/test/test_dispatch_std_any.cpp
index 5500b483..b35c805e 100644
--- a/test/test_dispatch_std_any.cpp
+++ b/test/test_dispatch_std_any.cpp
@@ -32,6 +32,18 @@ static_assert(
     detail::has_vptr<
         virtual_traits<const std::any&, default_registry>, const std::any&>);
 
+// A registry spelled on the parameter names the same parameter as the default
+// one, in each of the three forms.
+static_assert(detail::validate_method_parameter<
+              virtual_<const std::any&, default_registry>, default_registry,
+              void>::value);
+static_assert(
+    detail::validate_method_parameter<
+        virtual_<std::any&, default_registry>, default_registry, void>::value);
+static_assert(
+    detail::validate_method_parameter<
+        virtual_<std::any&&, default_registry>, default_registry, void>::value);
+
 MAKE_CLASSES();
 
 BOOST_OPENMETHOD(name, (virtual_<const std::any&>), std::string);
diff --git a/test/test_dispatch_type_erasure.cpp b/test/test_dispatch_type_erasure.cpp
index 83d82755..9554aa24 100644
--- a/test/test_dispatch_type_erasure.cpp
+++ b/test/test_dispatch_type_erasure.cpp
@@ -30,6 +30,24 @@ using erased_cref = te::any<Concept, const te::_self&>;
 static_assert(detail::has_vptr<
               virtual_traits<const erased&, default_registry>, const erased&>);
 
+// A registry spelled on the parameter names the same parameter as the default
+// one, for the owning any by reference and for the any references.
+static_assert(detail::validate_method_parameter<
+              virtual_<const erased&, default_registry>, default_registry,
+              void>::value);
+static_assert(
+    detail::validate_method_parameter<
+        virtual_<erased&, default_registry>, default_registry, void>::value);
+static_assert(
+    detail::validate_method_parameter<
+        virtual_<erased&&, default_registry>, default_registry, void>::value);
+static_assert(
+    detail::validate_method_parameter<
+        virtual_<erased_ref, default_registry>, default_registry, void>::value);
+static_assert(detail::validate_method_parameter<
+              virtual_<erased_cref, default_registry>, default_registry,
+              void>::value);
+
 #define MAKE_CLASSES()                                                         \
     struct Dog {                                                               \
         std::string name;                                                      \