diff --git a/include/pybind11/classh.h b/include/pybind11/classh.h
deleted file mode 100644
index a4c5509f6..000000000
--- a/include/pybind11/classh.h
+++ /dev/null
@@ -1,10 +0,0 @@
-#pragma once
-
-#include "detail/classh_type_casters.h"
-#include "smart_holder_poc.h"
-
-PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
-
-using pybindit::memory::smart_holder;
-
-PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)
diff --git a/include/pybind11/smart_holder_poc.h b/include/pybind11/detail/smart_holder_poc.h
similarity index 100%
rename from include/pybind11/smart_holder_poc.h
rename to include/pybind11/detail/smart_holder_poc.h
diff --git a/include/pybind11/detail/classh_type_casters.h b/include/pybind11/detail/smart_holder_type_casters.h
similarity index 99%
rename from include/pybind11/detail/classh_type_casters.h
rename to include/pybind11/detail/smart_holder_type_casters.h
index dd746021a..cd2e19efb 100644
--- a/include/pybind11/detail/classh_type_casters.h
+++ b/include/pybind11/detail/smart_holder_type_casters.h
@@ -2,11 +2,11 @@
 
 #include "../cast.h"
 #include "../pytypes.h"
-#include "../smart_holder_poc.h"
 #include "class.h"
 #include "common.h"
 #include "descr.h"
 #include "internals.h"
+#include "smart_holder_poc.h"
 
 #include <memory>
 #include <stdexcept>
@@ -15,6 +15,9 @@
 #include <utility>
 
 namespace pybind11 {
+
+using pybindit::memory::smart_holder;
+
 namespace detail {
 
 inline std::pair<bool, handle> find_existing_python_instance(void *src_void_ptr,
diff --git a/include/pybind11/smart_holder.h b/include/pybind11/smart_holder.h
new file mode 100644
index 000000000..fccc45ff1
--- /dev/null
+++ b/include/pybind11/smart_holder.h
@@ -0,0 +1,3 @@
+#pragma once
+
+#include "detail/smart_holder_type_casters.h"
diff --git a/tests/classh_module_local_0.cpp b/tests/classh_module_local_0.cpp
index 8a80711ed..fecf850cc 100644
--- a/tests/classh_module_local_0.cpp
+++ b/tests/classh_module_local_0.cpp
@@ -1,5 +1,5 @@
-#include <pybind11/classh.h>
 #include <pybind11/pybind11.h>
+#include <pybind11/smart_holder.h>
 
 #include <string>
 
diff --git a/tests/classh_module_local_1.cpp b/tests/classh_module_local_1.cpp
index 3c5948a82..c38577178 100644
--- a/tests/classh_module_local_1.cpp
+++ b/tests/classh_module_local_1.cpp
@@ -1,6 +1,6 @@
 // Identical to classh_module_local_2.cpp, except 2 replaced with 1.
-#include <pybind11/classh.h>
 #include <pybind11/pybind11.h>
+#include <pybind11/smart_holder.h>
 
 #include <string>
 
diff --git a/tests/classh_module_local_2.cpp b/tests/classh_module_local_2.cpp
index 7316f3eeb..2d33b04a0 100644
--- a/tests/classh_module_local_2.cpp
+++ b/tests/classh_module_local_2.cpp
@@ -1,6 +1,6 @@
 // Identical to classh_module_local_1.cpp, except 1 replaced with 2.
-#include <pybind11/classh.h>
 #include <pybind11/pybind11.h>
+#include <pybind11/smart_holder.h>
 
 #include <string>
 
diff --git a/tests/core/smart_holder_poc_test.cpp b/tests/core/smart_holder_poc_test.cpp
index a4123b915..dab47bded 100644
--- a/tests/core/smart_holder_poc_test.cpp
+++ b/tests/core/smart_holder_poc_test.cpp
@@ -1,4 +1,4 @@
-#include "pybind11/smart_holder_poc.h"
+#include "pybind11/detail/smart_holder_poc.h"
 
 #define CATCH_CONFIG_MAIN
 #include "catch.hpp"
diff --git a/tests/test_classh_inheritance.cpp b/tests/test_classh_inheritance.cpp
index 6f84202f6..ddaaefd51 100644
--- a/tests/test_classh_inheritance.cpp
+++ b/tests/test_classh_inheritance.cpp
@@ -1,6 +1,6 @@
 #include "pybind11_tests.h"
 
-#include <pybind11/classh.h>
+#include <pybind11/smart_holder.h>
 
 #include <memory>
 
diff --git a/tests/test_classh_wip.cpp b/tests/test_classh_wip.cpp
index 2b0a9bbcf..8a504f244 100644
--- a/tests/test_classh_wip.cpp
+++ b/tests/test_classh_wip.cpp
@@ -1,6 +1,6 @@
 #include "pybind11_tests.h"
 
-#include <pybind11/classh.h>
+#include <pybind11/smart_holder.h>
 
 #include <memory>
 #include <string>
diff --git a/tests/test_unique_ptr_member.cpp b/tests/test_unique_ptr_member.cpp
index 071241701..89ff00a30 100644
--- a/tests/test_unique_ptr_member.cpp
+++ b/tests/test_unique_ptr_member.cpp
@@ -1,6 +1,6 @@
 #include "pybind11_tests.h"
 
-#include <pybind11/classh.h>
+#include <pybind11/smart_holder.h>
 
 #include <memory>