diff --git a/README_smart_holder.rst b/README_smart_holder.rst
index cae40ff12..baf7b8ff0 100644
--- a/README_smart_holder.rst
+++ b/README_smart_holder.rst
@@ -164,17 +164,6 @@ of interest have made the switch, because then the code will continue to
 work in either mode.
 
 
-Using py::classh but with fallback to classic pybind11
-------------------------------------------------------
-
-This could be viewed as super-conservative mode, for situations in which
-compatibility with classic pybind11 (without smart_holder) is needed for
-some period of time. The main idea is to enable use of ``py::classh``
-and the associated ``PYBIND11_SMART_HOLDER_TYPE_CASTERS`` macro while
-still being able to build the same code with classic pybind11. Please see
-tests/test_classh_mock.cpp for an example.
-
-
 Trampolines and std::unique_ptr
 -------------------------------
 
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 3a7fbffad..1a1ca45da 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -112,7 +112,6 @@ set(PYBIND11_TEST_FILES
     test_class_sh_trampoline_unique_ptr.cpp
     test_class_sh_unique_ptr_member.cpp
     test_class_sh_virtual_py_cpp_mix.cpp
-    test_classh_mock.cpp
     test_constants_and_functions.cpp
     test_copy_move.cpp
     test_custom_type_casters.cpp
diff --git a/tests/test_classh_mock.cpp b/tests/test_classh_mock.cpp
deleted file mode 100644
index 078b6056e..000000000
--- a/tests/test_classh_mock.cpp
+++ /dev/null
@@ -1,42 +0,0 @@
-#include "pybind11_tests.h"
-
-// The main purpose of this test is to ensure the suggested BOILERPLATE code block below is
-// correct.
-
-// Copy this block of code into your project.
-// Replace FOOEXT with the name of your project.
-// BOILERPLATE BEGIN
-#ifdef FOOEXT_USING_PYBIND11_SMART_HOLDER
-#    include <pybind11/smart_holder.h>
-#else
-#    include <pybind11/pybind11.h>
-PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
-template <typename type_, typename... options>
-using classh = class_<type_, options...>;
-PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
-#    define PYBIND11_SMART_HOLDER_TYPE_CASTERS(...)
-#    define PYBIND11_TYPE_CASTER_BASE_HOLDER(...)
-#endif
-// BOILERPLATE END
-
-namespace {
-struct Foo0 {};
-struct Foo1 {};
-struct Foo2 {};
-} // namespace
-
-PYBIND11_TYPE_CASTER_BASE_HOLDER(Foo1, std::shared_ptr<Foo1>)
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(Foo2)
-
-TEST_SUBMODULE(classh_mock, m) {
-    // Uses std::unique_ptr<Foo0> as holder in conservative mode, py::smart_holder in progressive
-    // mode (if available).
-    py::class_<Foo0>(m, "Foo0").def(py::init<>());
-
-    // Always uses std::shared_ptr<Foo1> as holder.
-    py::class_<Foo1, std::shared_ptr<Foo1>>(m, "Foo1").def(py::init<>());
-
-    // Uses py::smart_holder if available, or std::unique_ptr<Foo2> if only pybind11 classic is
-    // available.
-    py::classh<Foo2>(m, "Foo2").def(py::init<>());
-}
diff --git a/tests/test_classh_mock.py b/tests/test_classh_mock.py
deleted file mode 100644
index 2c1d48754..000000000
--- a/tests/test_classh_mock.py
+++ /dev/null
@@ -1,11 +0,0 @@
-# -*- coding: utf-8 -*-
-
-from pybind11_tests import classh_mock as m
-
-
-def test_foobar():
-    # Not really testing anything in particular. The main purpose of this test is to ensure the
-    # suggested BOILERPLATE code block in test_classh_mock.cpp is correct.
-    assert m.Foo0()
-    assert m.Foo1()
-    assert m.Foo2()