diff --git a/include/pybind11/detail/classh_type_casters.h b/include/pybind11/detail/classh_type_casters.h
index a3708ab30..661a9fbfd 100644
--- a/include/pybind11/detail/classh_type_casters.h
+++ b/include/pybind11/detail/classh_type_casters.h
@@ -374,5 +374,23 @@ struct classh_type_caster<std::unique_ptr<T const>> : smart_holder_type_caster_l
     operator std::unique_ptr<T const>() { return this->loaded_as_unique_ptr(); }
 };
 
+#define PYBIND11_CLASSH_TYPE_CASTERS(T)                                                           \
+    namespace pybind11 {                                                                          \
+    namespace detail {                                                                            \
+    template <>                                                                                   \
+    class type_caster<T> : public classh_type_caster<T> {};                                       \
+    template <>                                                                                   \
+    class type_caster<std::shared_ptr<T>> : public classh_type_caster<std::shared_ptr<T>> {};     \
+    template <>                                                                                   \
+    class type_caster<std::shared_ptr<T const>>                                                   \
+        : public classh_type_caster<std::shared_ptr<T const>> {};                                 \
+    template <>                                                                                   \
+    class type_caster<std::unique_ptr<T>> : public classh_type_caster<std::unique_ptr<T>> {};     \
+    template <>                                                                                   \
+    class type_caster<std::unique_ptr<T const>>                                                   \
+        : public classh_type_caster<std::unique_ptr<T const>> {};                                 \
+    }                                                                                             \
+    }
+
 } // namespace detail
 } // namespace pybind11
diff --git a/tests/test_classh_wip.cpp b/tests/test_classh_wip.cpp
index 7bf976fca..79821f330 100644
--- a/tests/test_classh_wip.cpp
+++ b/tests/test_classh_wip.cpp
@@ -49,26 +49,7 @@ std::unique_ptr<mpty> unique_ptr_roundtrip(std::unique_ptr<mpty> obj) { return o
 } // namespace classh_wip
 } // namespace pybind11_tests
 
-namespace pybind11 {
-namespace detail {
-
-using mpty = pybind11_tests::classh_wip::mpty;
-
-template <>
-class type_caster<mpty> : public classh_type_caster<mpty> {};
-template <>
-class type_caster<std::shared_ptr<mpty>> : public classh_type_caster<std::shared_ptr<mpty>> {};
-template <>
-class type_caster<std::shared_ptr<mpty const>>
-    : public classh_type_caster<std::shared_ptr<mpty const>> {};
-template <>
-class type_caster<std::unique_ptr<mpty>> : public classh_type_caster<std::unique_ptr<mpty>> {};
-template <>
-class type_caster<std::unique_ptr<mpty const>>
-    : public classh_type_caster<std::unique_ptr<mpty const>> {};
-
-} // namespace detail
-} // namespace pybind11
+PYBIND11_CLASSH_TYPE_CASTERS(pybind11_tests::classh_wip::mpty)
 
 namespace pybind11_tests {
 namespace classh_wip {