diff --git a/tests/classh_module_local_0.cpp b/tests/class_sh_module_local_0.cpp
similarity index 60%
rename from tests/classh_module_local_0.cpp
rename to tests/class_sh_module_local_0.cpp
index c52cce8ab..8e007fd0e 100644
--- a/tests/classh_module_local_0.cpp
+++ b/tests/class_sh_module_local_0.cpp
@@ -4,7 +4,7 @@
 #include <string>
 
 namespace pybind11_tests {
-namespace classh_module_local {
+namespace class_sh_module_local {
 
 struct atyp { // Short for "any type".
     std::string mtxt;
@@ -14,13 +14,13 @@ std::string get_mtxt(const atyp &obj) { return obj.mtxt; }
 
 atyp rtrn_valu_atyp() { return atyp(); }
 
-} // namespace classh_module_local
+} // namespace class_sh_module_local
 } // namespace pybind11_tests
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::classh_module_local::atyp)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_module_local::atyp)
 
-PYBIND11_MODULE(classh_module_local_0, m) {
-    using namespace pybind11_tests::classh_module_local;
+PYBIND11_MODULE(class_sh_module_local_0, m) {
+    using namespace pybind11_tests::class_sh_module_local;
 
     m.def("get_mtxt", get_mtxt);
 
diff --git a/tests/classh_module_local_1.cpp b/tests/class_sh_module_local_1.cpp
similarity index 64%
rename from tests/classh_module_local_1.cpp
rename to tests/class_sh_module_local_1.cpp
index 8efa4a87a..22adb733d 100644
--- a/tests/classh_module_local_1.cpp
+++ b/tests/class_sh_module_local_1.cpp
@@ -1,11 +1,11 @@
-// Identical to classh_module_local_2.cpp, except 2 replaced with 1.
+// Identical to class_sh_module_local_2.cpp, except 2 replaced with 1.
 #include <pybind11/pybind11.h>
 #include <pybind11/smart_holder.h>
 
 #include <string>
 
 namespace pybind11_tests {
-namespace classh_module_local {
+namespace class_sh_module_local {
 
 struct atyp { // Short for "any type".
     std::string mtxt;
@@ -13,14 +13,14 @@ struct atyp { // Short for "any type".
 
 std::string get_mtxt(const atyp &obj) { return obj.mtxt; }
 
-} // namespace classh_module_local
+} // namespace class_sh_module_local
 } // namespace pybind11_tests
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::classh_module_local::atyp)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_module_local::atyp)
 
-PYBIND11_MODULE(classh_module_local_1, m) {
+PYBIND11_MODULE(class_sh_module_local_1, m) {
     namespace py = pybind11;
-    using namespace pybind11_tests::classh_module_local;
+    using namespace pybind11_tests::class_sh_module_local;
 
     py::class_<atyp, py::smart_holder>(m, "atyp", py::module_local())
         .def(py::init([](const std::string &mtxt) {
diff --git a/tests/classh_module_local_2.cpp b/tests/class_sh_module_local_2.cpp
similarity index 64%
rename from tests/classh_module_local_2.cpp
rename to tests/class_sh_module_local_2.cpp
index a6531ef41..e6f866267 100644
--- a/tests/classh_module_local_2.cpp
+++ b/tests/class_sh_module_local_2.cpp
@@ -1,11 +1,11 @@
-// Identical to classh_module_local_1.cpp, except 1 replaced with 2.
+// Identical to class_sh_module_local_1.cpp, except 1 replaced with 2.
 #include <pybind11/pybind11.h>
 #include <pybind11/smart_holder.h>
 
 #include <string>
 
 namespace pybind11_tests {
-namespace classh_module_local {
+namespace class_sh_module_local {
 
 struct atyp { // Short for "any type".
     std::string mtxt;
@@ -13,14 +13,14 @@ struct atyp { // Short for "any type".
 
 std::string get_mtxt(const atyp &obj) { return obj.mtxt; }
 
-} // namespace classh_module_local
+} // namespace class_sh_module_local
 } // namespace pybind11_tests
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::classh_module_local::atyp)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_module_local::atyp)
 
-PYBIND11_MODULE(classh_module_local_2, m) {
+PYBIND11_MODULE(class_sh_module_local_2, m) {
     namespace py = pybind11;
-    using namespace pybind11_tests::classh_module_local;
+    using namespace pybind11_tests::class_sh_module_local;
 
     py::class_<atyp, py::smart_holder>(m, "atyp", py::module_local())
         .def(py::init([](const std::string &mtxt) {
diff --git a/tests/test_classh_wip.cpp b/tests/test_class_sh_basic.cpp
similarity index 94%
rename from tests/test_classh_wip.cpp
rename to tests/test_class_sh_basic.cpp
index ae4a6f06b..488b033fc 100644
--- a/tests/test_classh_wip.cpp
+++ b/tests/test_class_sh_basic.cpp
@@ -6,7 +6,7 @@
 #include <string>
 
 namespace pybind11_tests {
-namespace classh_wip {
+namespace class_sh_basic {
 
 struct atyp { // Short for "any type".
     std::string mtxt;
@@ -46,15 +46,15 @@ std::string pass_uqcp_atyp(std::unique_ptr<atyp const> obj) { return "pass_uqcp:
 std::string get_mtxt(atyp const &obj) { return obj.mtxt; }
 std::unique_ptr<atyp> unique_ptr_roundtrip(std::unique_ptr<atyp> obj) { return obj; }
 
-} // namespace classh_wip
+} // namespace class_sh_basic
 } // namespace pybind11_tests
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::classh_wip::atyp)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_basic::atyp)
 
 namespace pybind11_tests {
-namespace classh_wip {
+namespace class_sh_basic {
 
-TEST_SUBMODULE(classh_wip, m) {
+TEST_SUBMODULE(class_sh_basic, m) {
     namespace py = pybind11;
 
     py::class_<atyp, py::smart_holder>(m, "atyp")
@@ -97,5 +97,5 @@ TEST_SUBMODULE(classh_wip, m) {
     m.def("unique_ptr_roundtrip", unique_ptr_roundtrip); // pass_uqmp_atyp, rtrn_uqmp_atyp
 }
 
-} // namespace classh_wip
+} // namespace class_sh_basic
 } // namespace pybind11_tests
diff --git a/tests/test_classh_wip.py b/tests/test_class_sh_basic.py
similarity index 98%
rename from tests/test_classh_wip.py
rename to tests/test_class_sh_basic.py
index b6f86d2bf..21a93b5dc 100644
--- a/tests/test_classh_wip.py
+++ b/tests/test_class_sh_basic.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 import pytest
 
-from pybind11_tests import classh_wip as m
+from pybind11_tests import class_sh_basic as m
 
 
 def test_atyp_constructors():
diff --git a/tests/test_classh_inheritance.cpp b/tests/test_class_sh_inheritance.cpp
similarity index 83%
rename from tests/test_classh_inheritance.cpp
rename to tests/test_class_sh_inheritance.cpp
index b6d7fc0b0..81049061f 100644
--- a/tests/test_classh_inheritance.cpp
+++ b/tests/test_class_sh_inheritance.cpp
@@ -5,7 +5,7 @@
 #include <memory>
 
 namespace pybind11_tests {
-namespace classh_inheritance {
+namespace class_sh_inheritance {
 
 template <int Id>
 struct base_template {
@@ -53,20 +53,20 @@ inline int pass_cptr_base2(base2 const *b) { return b->id() + 22; }
 inline int pass_cptr_drvd2(drvd2 const *d) { return d->id() + 23; }
 // clang-format on
 
-} // namespace classh_inheritance
+} // namespace class_sh_inheritance
 } // namespace pybind11_tests
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::classh_inheritance::base)
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::classh_inheritance::drvd)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_inheritance::base)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_inheritance::drvd)
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::classh_inheritance::base1)
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::classh_inheritance::base2)
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::classh_inheritance::drvd2)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_inheritance::base1)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_inheritance::base2)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_inheritance::drvd2)
 
 namespace pybind11_tests {
-namespace classh_inheritance {
+namespace class_sh_inheritance {
 
-TEST_SUBMODULE(classh_inheritance, m) {
+TEST_SUBMODULE(class_sh_inheritance, m) {
     py::class_<base, py::smart_holder>(m, "base");
     py::class_<drvd, base, py::smart_holder>(m, "drvd");
 
@@ -95,5 +95,5 @@ TEST_SUBMODULE(classh_inheritance, m) {
     m.def("pass_cptr_drvd2", pass_cptr_drvd2);
 }
 
-} // namespace classh_inheritance
+} // namespace class_sh_inheritance
 } // namespace pybind11_tests
diff --git a/tests/test_classh_inheritance.py b/tests/test_class_sh_inheritance.py
similarity index 96%
rename from tests/test_classh_inheritance.py
rename to tests/test_class_sh_inheritance.py
index cf72c5bc4..69f9131d7 100644
--- a/tests/test_classh_inheritance.py
+++ b/tests/test_class_sh_inheritance.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-from pybind11_tests import classh_inheritance as m
+from pybind11_tests import class_sh_inheritance as m
 
 
 def test_rtrn_mptr_drvd_pass_cptr_base():
diff --git a/tests/test_classh_module_local.py b/tests/test_class_sh_module_local.py
similarity index 84%
rename from tests/test_classh_module_local.py
rename to tests/test_class_sh_module_local.py
index f7113efe5..aa4d1f3c5 100644
--- a/tests/test_classh_module_local.py
+++ b/tests/test_class_sh_module_local.py
@@ -1,9 +1,9 @@
 # -*- coding: utf-8 -*-
 import pytest
 
-import classh_module_local_0 as m0
-import classh_module_local_1 as m1
-import classh_module_local_2 as m2
+import class_sh_module_local_0 as m0
+import class_sh_module_local_1 as m1
+import class_sh_module_local_2 as m2
 
 
 def test_cross_module_get_mtxt():
diff --git a/tests/test_unique_ptr_member.cpp b/tests/test_class_sh_unique_ptr_member.cpp
similarity index 83%
rename from tests/test_unique_ptr_member.cpp
rename to tests/test_class_sh_unique_ptr_member.cpp
index a9484c0fc..0da05f4e3 100644
--- a/tests/test_unique_ptr_member.cpp
+++ b/tests/test_class_sh_unique_ptr_member.cpp
@@ -5,7 +5,7 @@
 #include <memory>
 
 namespace pybind11_tests {
-namespace unique_ptr_member {
+namespace class_sh_unique_ptr_member {
 
 class pointee { // NOT copyable.
 public:
@@ -37,15 +37,15 @@ private:
     std::unique_ptr<pointee> ptr_;
 };
 
-} // namespace unique_ptr_member
+} // namespace class_sh_unique_ptr_member
 } // namespace pybind11_tests
 
-PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::unique_ptr_member::pointee)
+PYBIND11_SMART_HOLDER_TYPE_CASTERS(pybind11_tests::class_sh_unique_ptr_member::pointee)
 
 namespace pybind11_tests {
-namespace unique_ptr_member {
+namespace class_sh_unique_ptr_member {
 
-TEST_SUBMODULE(unique_ptr_member, m) {
+TEST_SUBMODULE(class_sh_unique_ptr_member, m) {
     py::class_<pointee, py::smart_holder>(m, "pointee")
         .def(py::init<>())
         .def("get_int", &pointee::get_int);
@@ -59,5 +59,5 @@ TEST_SUBMODULE(unique_ptr_member, m) {
         .def("give_up_ownership_via_shared_ptr", &ptr_owner::give_up_ownership_via_shared_ptr);
 }
 
-} // namespace unique_ptr_member
+} // namespace class_sh_unique_ptr_member
 } // namespace pybind11_tests
diff --git a/tests/test_unique_ptr_member.py b/tests/test_class_sh_unique_ptr_member.py
similarity index 93%
rename from tests/test_unique_ptr_member.py
rename to tests/test_class_sh_unique_ptr_member.py
index 5ced1b3ae..5537ac7a9 100644
--- a/tests/test_unique_ptr_member.py
+++ b/tests/test_class_sh_unique_ptr_member.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 import pytest
 
-from pybind11_tests import unique_ptr_member as m
+from pybind11_tests import class_sh_unique_ptr_member as m
 
 
 def test_make_unique_pointee():