diff --git a/include/pybind11/detail/init.h b/include/pybind11/detail/init.h
index 7f620f27a..23e05bacf 100644
--- a/include/pybind11/detail/init.h
+++ b/include/pybind11/detail/init.h
@@ -168,6 +168,42 @@ void construct(value_and_holder &v_h, Alias<Class> &&result, bool) {
     v_h.value_ptr() = new Alias<Class>(std::move(result));
 }
 
+//DETAIL/SMART_HOLDER_INIT_H/BEGIN/////////////////////////////////////////////////////////////////
+
+template <typename Class, typename D = std::default_delete<Cpp<Class>>,
+          detail::enable_if_t<detail::is_smart_holder_type_caster<Cpp<Class>>::value, int> = 0>
+void construct(value_and_holder &v_h, std::unique_ptr<Cpp<Class>, D> &&unq_ptr, bool need_alias) {
+    auto *ptr = unq_ptr.get();
+    no_nullptr(ptr);
+    // If we need an alias, check that the held pointer is actually an alias instance
+    if (Class::has_alias && need_alias && !is_alias<Class>(ptr))
+        throw type_error("pybind11::init(): construction failed: returned holder-wrapped instance "
+                         "is not an alias instance");
+
+    auto smhldr = pybindit::memory::smart_holder::from_unique_ptr(std::move(unq_ptr));
+
+    v_h.value_ptr() = ptr;
+    v_h.type->init_instance(v_h.inst, &smhldr);
+}
+
+template <typename Class,
+          detail::enable_if_t<detail::is_smart_holder_type_caster<Cpp<Class>>::value, int> = 0>
+void construct(value_and_holder &v_h, std::shared_ptr<Cpp<Class>> &&shd_ptr, bool need_alias) {
+    auto *ptr = shd_ptr.get();
+    no_nullptr(ptr);
+    // If we need an alias, check that the held pointer is actually an alias instance
+    if (Class::has_alias && need_alias && !is_alias<Class>(ptr))
+        throw type_error("pybind11::init(): construction failed: returned holder-wrapped instance "
+                         "is not an alias instance");
+
+    auto smhldr = pybindit::memory::smart_holder::from_shared_ptr(std::move(shd_ptr));
+
+    v_h.value_ptr() = ptr;
+    v_h.type->init_instance(v_h.inst, &smhldr);
+}
+
+//DETAIL/SMART_HOLDER_INIT_H/END///////////////////////////////////////////////////////////////////
+
 // Implementing class for py::init<...>()
 template <typename... Args>
 struct constructor {
diff --git a/tests/test_class_sh_factory_constructors.cpp b/tests/test_class_sh_factory_constructors.cpp
index 1cf45087f..33bb50af2 100644
--- a/tests/test_class_sh_factory_constructors.cpp
+++ b/tests/test_class_sh_factory_constructors.cpp
@@ -63,11 +63,11 @@ PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constru
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_mref)
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_cptr)
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_mptr)
-// PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_shmp)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_shmp)
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_shcp)
-// PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_uqmp)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_uqmp)
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_uqcp)
-// PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_udmp)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_udmp)
 PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_udcp)
 
 TEST_SUBMODULE(class_sh_factory_constructors, m) {
@@ -103,23 +103,18 @@ TEST_SUBMODULE(class_sh_factory_constructors, m) {
         .def(py::init(&rtrn_mptr))
         .def("get_mtxt", get_mtxt<atyp_mptr>);
 
-    // NEEDED FOR FEATURE PARITY: shmp
-    py::class_<atyp_shmp, std::shared_ptr<atyp_shmp>>(m, "atyp_shmp")
-        // py::classh<atyp_shmp>(m, "atyp_shmp")
-        // classh: ... cannot pass object of non-trivial type ...
+    py::classh<atyp_shmp>(m, "atyp_shmp")
         .def(py::init(&rtrn_shmp))
         .def("get_mtxt", get_mtxt<atyp_shmp>);
 
-    // py::class_<atyp_shcp, std::shared_ptr<atyp_shcp>>(m, "atyp_shcp")
     py::classh<atyp_shcp>(m, "atyp_shcp")
+        // py::class_<atyp_shcp, std::shared_ptr<atyp_shcp>>(m, "atyp_shcp")
         // class_: ... must return a compatible ...
         // classh: ... cannot pass object of non-trivial type ...
         // .def(py::init(&rtrn_shcp))
         .def("get_mtxt", get_mtxt<atyp_shcp>);
 
-    // NEEDED FOR FEATURE PARITY: uqmp
-    py::class_<atyp_uqmp>(m, "atyp_uqmp")
-        // classh: ... cannot pass object of non-trivial type ...
+    py::classh<atyp_uqmp>(m, "atyp_uqmp")
         .def(py::init(&rtrn_uqmp))
         .def("get_mtxt", get_mtxt<atyp_uqmp>);
 
@@ -129,15 +124,12 @@ TEST_SUBMODULE(class_sh_factory_constructors, m) {
         // .def(py::init(&rtrn_uqcp))
         .def("get_mtxt", get_mtxt<atyp_uqcp>);
 
-    // NEEDED FOR FEATURE PARITY: udmp
-    py::class_<atyp_udmp, std::unique_ptr<atyp_udmp, sddm>>(m, "atyp_udmp")
-        // py::classh<atyp_udmp>(m, "atyp_udmp")
-        // classh: ... cannot pass object of non-trivial type ...
+    py::classh<atyp_udmp>(m, "atyp_udmp")
         .def(py::init(&rtrn_udmp))
         .def("get_mtxt", get_mtxt<atyp_udmp>);
 
-    // py::class_<atyp_udcp, std::unique_ptr<atyp_udcp, sddc>>(m, "atyp_udcp")
     py::classh<atyp_udcp>(m, "atyp_udcp")
+        // py::class_<atyp_udcp, std::unique_ptr<atyp_udcp, sddc>>(m, "atyp_udcp")
         // class_: ... must return a compatible ...
         // classh: ... cannot pass object of non-trivial type ...
         // .def(py::init(&rtrn_udcp))