diff --git a/tests/test_class_sh_basic.cpp b/tests/test_class_sh_basic.cpp
index ef08f7e0e..c1cacccf9 100644
--- a/tests/test_class_sh_basic.cpp
+++ b/tests/test_class_sh_basic.cpp
@@ -40,14 +40,14 @@ std::unique_ptr<atyp const> rtrn_uqcp_atyp() { return std::unique_ptr<atyp const
 std::string pass_uqmp_atyp(std::unique_ptr<atyp      > obj) { return "pass_uqmp:" + obj->mtxt; }
 std::string pass_uqcp_atyp(std::unique_ptr<atyp const> obj) { return "pass_uqcp:" + obj->mtxt; }
 
-struct uqmd : std::default_delete<atyp      > {};
-struct uqcd : std::default_delete<atyp const> {};
+struct sddm : std::default_delete<atyp      > {};
+struct sddc : std::default_delete<atyp const> {};
 
-std::unique_ptr<atyp,       uqmd> rtrn_uqmp_del_atyp() { return std::unique_ptr<atyp,       uqmd>(new atyp{"rtrn_uqmp_del"}); }
-std::unique_ptr<atyp const, uqcd> rtrn_uqcp_del_atyp() { return std::unique_ptr<atyp const, uqcd>(new atyp{"rtrn_uqcp_del"}); }
+std::unique_ptr<atyp,       sddm> rtrn_udmp_atyp() { return std::unique_ptr<atyp,       sddm>(new atyp{"rtrn_udmp"}); }
+std::unique_ptr<atyp const, sddc> rtrn_udcp_atyp() { return std::unique_ptr<atyp const, sddc>(new atyp{"rtrn_udcp"}); }
 
-std::string pass_uqmp_del_atyp(std::unique_ptr<atyp,       uqmd> obj) { return "pass_uqmp_del:" + obj->mtxt; }
-std::string pass_uqcp_del_atyp(std::unique_ptr<atyp const, uqcd> obj) { return "pass_uqcp_del:" + obj->mtxt; }
+std::string pass_udmp_atyp(std::unique_ptr<atyp,       sddm> obj) { return "pass_udmp:" + obj->mtxt; }
+std::string pass_udcp_atyp(std::unique_ptr<atyp const, sddc> obj) { return "pass_udcp:" + obj->mtxt; }
 
 // clang-format on
 
@@ -98,11 +98,11 @@ TEST_SUBMODULE(class_sh_basic, m) {
     m.def("pass_uqmp_atyp", pass_uqmp_atyp);
     m.def("pass_uqcp_atyp", pass_uqcp_atyp);
 
-    m.def("rtrn_uqmp_del_atyp", rtrn_uqmp_del_atyp);
-    m.def("rtrn_uqcp_del_atyp", rtrn_uqcp_del_atyp);
+    m.def("rtrn_udmp_atyp", rtrn_udmp_atyp);
+    m.def("rtrn_udcp_atyp", rtrn_udcp_atyp);
 
-    m.def("pass_uqmp_del_atyp", pass_uqmp_del_atyp);
-    m.def("pass_uqcp_del_atyp", pass_uqcp_del_atyp);
+    m.def("pass_udmp_atyp", pass_udmp_atyp);
+    m.def("pass_udcp_atyp", pass_udcp_atyp);
 
     // Helpers for testing.
     // These require selected functions above to work first, as indicated:
diff --git a/tests/test_class_sh_basic.py b/tests/test_class_sh_basic.py
index 6383a408c..1cc9264d6 100644
--- a/tests/test_class_sh_basic.py
+++ b/tests/test_class_sh_basic.py
@@ -52,24 +52,26 @@ def test_load_unique_ptr():
 
 
 def test_cast_unique_ptr_with_deleter():
-    assert m.get_mtxt(m.rtrn_uqmp_del_atyp()) == "rtrn_uqmp_del"
-    assert m.get_mtxt(m.rtrn_uqcp_del_atyp()) == "rtrn_uqcp_del"
+    assert m.get_mtxt(m.rtrn_udmp_atyp()) == "rtrn_udmp"
+    assert m.get_mtxt(m.rtrn_udcp_atyp()) == "rtrn_udcp"
 
 
 def test_load_unique_ptr_with_deleter():
-    assert m.pass_uqmp_del_atyp(m.rtrn_uqmp_del_atyp()) == "pass_uqmp_del:rtrn_uqmp_del"
-    assert m.pass_uqcp_del_atyp(m.rtrn_uqcp_del_atyp()) == "pass_uqcp_del:rtrn_uqcp_del"
+    assert m.pass_udmp_atyp(m.rtrn_udmp_atyp()) == "pass_udmp:rtrn_udmp"
+    assert m.pass_udcp_atyp(m.rtrn_udcp_atyp()) == "pass_udcp:rtrn_udcp"
 
 
 @pytest.mark.parametrize(
-    "pass_atyp, argm, rtrn",
+    "rtrn_atyp, pass_atyp, rtrn",
     [
-        (m.pass_uqmp_atyp, "Uqmp", "pass_uqmp:Uqmp"),
-        (m.pass_uqcp_atyp, "Uqcp", "pass_uqcp:Uqcp"),
+        (m.rtrn_uqmp_atyp, m.pass_uqmp_atyp, "pass_uqmp:rtrn_uqmp"),
+        (m.rtrn_uqcp_atyp, m.pass_uqcp_atyp, "pass_uqcp:rtrn_uqcp"),
+        (m.rtrn_udmp_atyp, m.pass_udmp_atyp, "pass_udmp:rtrn_udmp"),
+        (m.rtrn_udcp_atyp, m.pass_udcp_atyp, "pass_udcp:rtrn_udcp"),
     ],
 )
-def test_pass_unique_ptr_disowns(pass_atyp, argm, rtrn):
-    obj = m.atyp(argm)
+def test_pass_unique_ptr_disowns(rtrn_atyp, pass_atyp, rtrn):
+    obj = rtrn_atyp()
     assert pass_atyp(obj) == rtrn
     with pytest.raises(RuntimeError) as exc_info:
         m.pass_uqmp_atyp(obj)
diff --git a/tests/test_class_sh_factory_constructors.cpp b/tests/test_class_sh_factory_constructors.cpp
new file mode 100644
index 000000000..a820b4268
--- /dev/null
+++ b/tests/test_class_sh_factory_constructors.cpp
@@ -0,0 +1,129 @@
+#include "pybind11_tests.h"
+
+#include <pybind11/smart_holder.h>
+
+#include <memory>
+#include <string>
+
+namespace pybind11_tests {
+namespace test_class_sh_factory_constructors {
+
+template <int> // Using int as a trick to easily generate a series of types.
+struct atyp {  // Short for "any type".
+    std::string mtxt;
+};
+
+template <typename T>
+std::string get_mtxt(const T &obj) {
+    return obj.mtxt;
+}
+
+using atyp_valu = atyp<0x0>;
+using atyp_rref = atyp<0x1>;
+using atyp_cref = atyp<0x2>;
+using atyp_mref = atyp<0x3>;
+using atyp_cptr = atyp<0x4>;
+using atyp_mptr = atyp<0x5>;
+using atyp_shmp = atyp<0x6>;
+using atyp_shcp = atyp<0x7>;
+using atyp_uqmp = atyp<0x8>;
+using atyp_uqcp = atyp<0x9>;
+using atyp_udmp = atyp<0xA>;
+using atyp_udcp = atyp<0xB>;
+
+// clang-format off
+
+atyp_valu        rtrn_valu() { atyp_valu obj{"Valu"}; return obj; }
+atyp_rref&&      rtrn_rref() { static atyp_rref obj; obj.mtxt = "Rref"; return std::move(obj); }
+atyp_cref const& rtrn_cref() { static atyp_cref obj; obj.mtxt = "Cref"; return obj; }
+atyp_mref&       rtrn_mref() { static atyp_mref obj; obj.mtxt = "Mref"; return obj; }
+atyp_cptr const* rtrn_cptr() { return new atyp_cptr{"Cptr"}; }
+atyp_mptr*       rtrn_mptr() { return new atyp_mptr{"Mptr"}; }
+
+std::shared_ptr<atyp_shmp>       rtrn_shmp() { return std::shared_ptr<atyp_shmp      >(new atyp_shmp{"Shmp"}); }
+std::shared_ptr<atyp_shcp const> rtrn_shcp() { return std::shared_ptr<atyp_shcp const>(new atyp_shcp{"Shcp"}); }
+
+std::unique_ptr<atyp_uqmp>       rtrn_uqmp() { return std::unique_ptr<atyp_uqmp      >(new atyp_uqmp{"Uqmp"}); }
+std::unique_ptr<atyp_uqcp const> rtrn_uqcp() { return std::unique_ptr<atyp_uqcp const>(new atyp_uqcp{"Uqcp"}); }
+
+struct sddm : std::default_delete<atyp_udmp      > {};
+struct sddc : std::default_delete<atyp_udcp const> {};
+
+std::unique_ptr<atyp_udmp,       sddm> rtrn_udmp() { return std::unique_ptr<atyp_udmp,       sddm>(new atyp_udmp{"Udmp"}); }
+std::unique_ptr<atyp_udcp const, sddc> rtrn_udcp() { return std::unique_ptr<atyp_udcp const, sddc>(new atyp_udcp{"Udcp"}); }
+
+// clang-format on
+
+} // namespace test_class_sh_factory_constructors
+} // namespace pybind11_tests
+
+// PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_valu)
+// PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_rref)
+// PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::test_class_sh_factory_constructors::atyp_cref)
+// 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_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_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_udcp)
+
+TEST_SUBMODULE(class_sh_factory_constructors, m) {
+    using namespace pybind11_tests::test_class_sh_factory_constructors;
+
+    py::class_<atyp_valu>(m, "atyp_valu")
+        .def(py::init(&rtrn_valu))
+        .def("get_mtxt", get_mtxt<atyp_valu>);
+
+    py::class_<atyp_rref>(m, "atyp_rref")
+        .def(py::init(&rtrn_rref))
+        .def("get_mtxt", get_mtxt<atyp_rref>);
+
+    py::class_<atyp_cref>(m, "atyp_cref")
+        // ... must return a compatible ...
+        // .def(py::init(&rtrn_cref))
+        .def("get_mtxt", get_mtxt<atyp_cref>);
+
+    py::class_<atyp_mref>(m, "atyp_mref")
+        // ... must return a compatible ...
+        // .def(py::init(&rtrn_mref))
+        .def("get_mtxt", get_mtxt<atyp_mref>);
+
+    py::class_<atyp_cptr>(m, "atyp_cptr")
+        // ... must return a compatible ...
+        // .def(py::init(&rtrn_cptr))
+        .def("get_mtxt", get_mtxt<atyp_cptr>);
+
+    py::class_<atyp_mptr>(m, "atyp_mptr")
+        .def(py::init(&rtrn_mptr))
+        .def("get_mtxt", get_mtxt<atyp_mptr>);
+
+    py::class_<atyp_shmp, std::shared_ptr<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")
+        // ... must return a compatible ...
+        // .def(py::init(&rtrn_shcp))
+        .def("get_mtxt", get_mtxt<atyp_shcp>);
+
+    py::class_<atyp_uqmp>(m, "atyp_uqmp")
+        .def(py::init(&rtrn_uqmp))
+        .def("get_mtxt", get_mtxt<atyp_uqmp>);
+
+    py::class_<atyp_uqcp>(m, "atyp_uqcp")
+        // ... cannot pass object of non-trivial type ...
+        // .def(py::init(&rtrn_uqcp))
+        .def("get_mtxt", get_mtxt<atyp_uqcp>);
+
+    py::class_<atyp_udmp, std::unique_ptr<atyp_udmp, sddm>>(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")
+        // ... must return a compatible ...
+        // .def(py::init(&rtrn_udcp))
+        .def("get_mtxt", get_mtxt<atyp_udcp>);
+}
diff --git a/tests/test_class_sh_factory_constructors.py b/tests/test_class_sh_factory_constructors.py
new file mode 100644
index 000000000..c28db561e
--- /dev/null
+++ b/tests/test_class_sh_factory_constructors.py
@@ -0,0 +1,18 @@
+# -*- coding: utf-8 -*-
+
+from pybind11_tests import class_sh_factory_constructors as m
+
+
+def test_atyp_factories():
+    assert m.atyp_valu().get_mtxt() == "Valu"
+    assert m.atyp_rref().get_mtxt() == "Rref"
+    # sert m.atyp_cref().get_mtxt() == "Cref"
+    # sert m.atyp_mref().get_mtxt() == "Mref"
+    # sert m.atyp_cptr().get_mtxt() == "Cptr"
+    assert m.atyp_mptr().get_mtxt() == "Mptr"
+    assert m.atyp_shmp().get_mtxt() == "Shmp"
+    # sert m.atyp_shcp().get_mtxt() == "Shcp"
+    assert m.atyp_uqmp().get_mtxt() == "Uqmp"
+    # sert m.atyp_uqcp().get_mtxt() == "Uqcp"
+    assert m.atyp_udmp().get_mtxt() == "Udmp"
+    # sert m.atyp_udcp().get_mtxt() == "Udcp"