diff --git a/include/pybind11/detail/using_smart_holder.h b/include/pybind11/detail/using_smart_holder.h
index 1762944d0..ef95ea7fc 100644
--- a/include/pybind11/detail/using_smart_holder.h
+++ b/include/pybind11/detail/using_smart_holder.h
@@ -4,11 +4,17 @@
 
 #pragma once
 
-#include "common.h"
-#include "smart_holder_poc.h"
+#include "internals.h"
+
+#ifdef PYBIND11_HAVE_INTERNALS_WITH_SMART_HOLDER_SUPPORT
+
+#    include "common.h"
+#    include "smart_holder_poc.h"
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
 using pybindit::memory::smart_holder;
 
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
+
+#endif
diff --git a/include/pybind11/smart_holder.h b/include/pybind11/smart_holder.h
index 8d776d970..6ca9e7d3d 100644
--- a/include/pybind11/smart_holder.h
+++ b/include/pybind11/smart_holder.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2024 The Pybind Development Team.
+// Copyright (c) 2021-2024 The Pybind Development Team.
 // All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
@@ -13,6 +13,8 @@
 
 PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
 
+#ifdef PYBIND11_HAVE_INTERNALS_WITH_SMART_HOLDER_SUPPORT
+
 // Supports easier switching between py::class_<T> and py::class_<T, py::smart_holder>:
 // users can simply replace the `_` in `class_` with `h` or vice versa.
 template <typename type_, typename... options>
@@ -21,4 +23,6 @@ public:
     using class_<type_, smart_holder, options...>::class_;
 };
 
+#endif
+
 PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
diff --git a/tests/test_class_sh_trampoline_basic.cpp b/tests/test_class_sh_trampoline_basic.cpp
index 8627a8d6d..856f274c2 100644
--- a/tests/test_class_sh_trampoline_basic.cpp
+++ b/tests/test_class_sh_trampoline_basic.cpp
@@ -63,6 +63,7 @@ int AddInCppUniquePtr(std::unique_ptr<Abase<SerNo>> obj, int other_val) {
 
 template <int SerNo>
 void wrap(py::module_ m, const char *py_class_name) {
+#ifdef PYBIND11_HAVE_INTERNALS_WITH_SMART_HOLDER_SUPPORT
     py::classh<Abase<SerNo>, AbaseAlias<SerNo>>(m, py_class_name)
         .def(py::init<int>(), py::arg("val"))
         .def("Get", &Abase<SerNo>::Get)
@@ -71,6 +72,7 @@ void wrap(py::module_ m, const char *py_class_name) {
     m.def("AddInCppRawPtr", AddInCppRawPtr<SerNo>, py::arg("obj"), py::arg("other_val"));
     m.def("AddInCppSharedPtr", AddInCppSharedPtr<SerNo>, py::arg("obj"), py::arg("other_val"));
     m.def("AddInCppUniquePtr", AddInCppUniquePtr<SerNo>, py::arg("obj"), py::arg("other_val"));
+#endif
 }
 
 } // namespace class_sh_trampoline_basic