diff --git a/Modules/_winapi.c b/Modules/_winapi.c
index 852e0a7d7b4..cdb45c23e78 100644
--- a/Modules/_winapi.c
+++ b/Modules/_winapi.c
@@ -995,13 +995,14 @@ process ID, and thread ID.
 [clinic start generated code]*/
 
 static PyObject *
-_winapi_CreateProcess_impl(PyObject *module, Py_UNICODE *application_name,
+_winapi_CreateProcess_impl(PyObject *module,
+                           const Py_UNICODE *application_name,
                            PyObject *command_line, PyObject *proc_attrs,
                            PyObject *thread_attrs, BOOL inherit_handles,
                            DWORD creation_flags, PyObject *env_mapping,
-                           Py_UNICODE *current_directory,
+                           const Py_UNICODE *current_directory,
                            PyObject *startup_info)
-/*[clinic end generated code: output=2ecaab46a05e3123 input=42ac293eaea03fc4]*/
+/*[clinic end generated code: output=9b2423a609230132 input=42ac293eaea03fc4]*/
 {
     PyObject *ret = NULL;
     BOOL result;
diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
index 1bfc4dd95bf..f5f461b7564 100644
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -1712,9 +1712,9 @@ some other type.
 [clinic start generated code]*/
 
 static PyObject *
-array_array_fromunicode_impl(arrayobject *self, Py_UNICODE *ustr,
+array_array_fromunicode_impl(arrayobject *self, const Py_UNICODE *ustr,
                              Py_ssize_clean_t ustr_length)
-/*[clinic end generated code: output=ebb72fc16975e06d input=150f00566ffbca6e]*/
+/*[clinic end generated code: output=cf2f662908e2befc input=150f00566ffbca6e]*/
 {
     char typecode;
 
diff --git a/Modules/clinic/_winapi.c.h b/Modules/clinic/_winapi.c.h
index 241c18e5a25..79d85ff6bb0 100644
--- a/Modules/clinic/_winapi.c.h
+++ b/Modules/clinic/_winapi.c.h
@@ -300,25 +300,26 @@ PyDoc_STRVAR(_winapi_CreateProcess__doc__,
     {"CreateProcess", (PyCFunction)(void(*)(void))_winapi_CreateProcess, METH_FASTCALL, _winapi_CreateProcess__doc__},
 
 static PyObject *
-_winapi_CreateProcess_impl(PyObject *module, Py_UNICODE *application_name,
+_winapi_CreateProcess_impl(PyObject *module,
+                           const Py_UNICODE *application_name,
                            PyObject *command_line, PyObject *proc_attrs,
                            PyObject *thread_attrs, BOOL inherit_handles,
                            DWORD creation_flags, PyObject *env_mapping,
-                           Py_UNICODE *current_directory,
+                           const Py_UNICODE *current_directory,
                            PyObject *startup_info);
 
 static PyObject *
 _winapi_CreateProcess(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    Py_UNICODE *application_name;
+    const Py_UNICODE *application_name;
     PyObject *command_line;
     PyObject *proc_attrs;
     PyObject *thread_attrs;
     BOOL inherit_handles;
     DWORD creation_flags;
     PyObject *env_mapping;
-    Py_UNICODE *current_directory;
+    const Py_UNICODE *current_directory;
     PyObject *startup_info;
 
     if (!_PyArg_ParseStack(args, nargs, "ZOOOikOZO:CreateProcess",
@@ -943,4 +944,4 @@ _winapi_GetFileType(PyObject *module, PyObject *const *args, Py_ssize_t nargs, P
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=1568ad4bd625f2af input=a9049054013a1b77]*/
+/*[clinic end generated code: output=145d0d362167c1b1 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/arraymodule.c.h b/Modules/clinic/arraymodule.c.h
index aa9938868f4..0d1008743e1 100644
--- a/Modules/clinic/arraymodule.c.h
+++ b/Modules/clinic/arraymodule.c.h
@@ -376,14 +376,14 @@ PyDoc_STRVAR(array_array_fromunicode__doc__,
     {"fromunicode", (PyCFunction)array_array_fromunicode, METH_O, array_array_fromunicode__doc__},
 
 static PyObject *
-array_array_fromunicode_impl(arrayobject *self, Py_UNICODE *ustr,
+array_array_fromunicode_impl(arrayobject *self, const Py_UNICODE *ustr,
                              Py_ssize_clean_t ustr_length);
 
 static PyObject *
 array_array_fromunicode(arrayobject *self, PyObject *arg)
 {
     PyObject *return_value = NULL;
-    Py_UNICODE *ustr;
+    const Py_UNICODE *ustr;
     Py_ssize_clean_t ustr_length;
 
     if (!PyArg_Parse(arg, "u#:fromunicode", &ustr, &ustr_length)) {
@@ -505,4 +505,4 @@ PyDoc_STRVAR(array_arrayiterator___setstate____doc__,
 
 #define ARRAY_ARRAYITERATOR___SETSTATE___METHODDEF    \
     {"__setstate__", (PyCFunction)array_arrayiterator___setstate__, METH_O, array_arrayiterator___setstate____doc__},
-/*[clinic end generated code: output=3a4c6f3deb597bfd input=a9049054013a1b77]*/
+/*[clinic end generated code: output=3d2bb1aa81541cbd input=a9049054013a1b77]*/
diff --git a/Modules/clinic/posixmodule.c.h b/Modules/clinic/posixmodule.c.h
index 80690703ee2..6d523bcc9ff 100644
--- a/Modules/clinic/posixmodule.c.h
+++ b/Modules/clinic/posixmodule.c.h
@@ -1329,7 +1329,7 @@ PyDoc_STRVAR(os_system__doc__,
     {"system", (PyCFunction)(void(*)(void))os_system, METH_FASTCALL|METH_KEYWORDS, os_system__doc__},
 
 static long
-os_system_impl(PyObject *module, Py_UNICODE *command);
+os_system_impl(PyObject *module, const Py_UNICODE *command);
 
 static PyObject *
 os_system(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
@@ -1337,7 +1337,7 @@ os_system(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *k
     PyObject *return_value = NULL;
     static const char * const _keywords[] = {"command", NULL};
     static _PyArg_Parser _parser = {"u:system", _keywords, 0};
-    Py_UNICODE *command;
+    const Py_UNICODE *command;
     long _return_value;
 
     if (!_PyArg_ParseStackAndKeywords(args, nargs, kwnames, &_parser,
@@ -5327,7 +5327,8 @@ PyDoc_STRVAR(os_startfile__doc__,
     {"startfile", (PyCFunction)(void(*)(void))os_startfile, METH_FASTCALL|METH_KEYWORDS, os_startfile__doc__},
 
 static PyObject *
-os_startfile_impl(PyObject *module, path_t *filepath, Py_UNICODE *operation);
+os_startfile_impl(PyObject *module, path_t *filepath,
+                  const Py_UNICODE *operation);
 
 static PyObject *
 os_startfile(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
@@ -5336,7 +5337,7 @@ os_startfile(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject
     static const char * const _keywords[] = {"filepath", "operation", NULL};
     static _PyArg_Parser _parser = {"O&|u:startfile", _keywords, 0};
     path_t filepath = PATH_T_INITIALIZE("startfile", "filepath", 0, 0);
-    Py_UNICODE *operation = NULL;
+    const Py_UNICODE *operation = NULL;
 
     if (!_PyArg_ParseStackAndKeywords(args, nargs, kwnames, &_parser,
         path_converter, &filepath, &operation)) {
@@ -6757,4 +6758,4 @@ exit:
 #ifndef OS_GETRANDOM_METHODDEF
     #define OS_GETRANDOM_METHODDEF
 #endif /* !defined(OS_GETRANDOM_METHODDEF) */
-/*[clinic end generated code: output=d62c0bb988141e70 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=7ebb53d872bab149 input=a9049054013a1b77]*/
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index d05724a50d1..0ea391e799b 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -4215,8 +4215,8 @@ Execute the command in a subshell.
 [clinic start generated code]*/
 
 static long
-os_system_impl(PyObject *module, Py_UNICODE *command)
-/*[clinic end generated code: output=96c4dffee36dfb48 input=303f5ce97df606b0]*/
+os_system_impl(PyObject *module, const Py_UNICODE *command)
+/*[clinic end generated code: output=5b7c3599c068ca42 input=303f5ce97df606b0]*/
 {
     long result;
     Py_BEGIN_ALLOW_THREADS
@@ -11224,8 +11224,9 @@ the underlying Win32 ShellExecute function doesn't work if it is.
 [clinic start generated code]*/
 
 static PyObject *
-os_startfile_impl(PyObject *module, path_t *filepath, Py_UNICODE *operation)
-/*[clinic end generated code: output=912ceba79acfa1c9 input=63950bf2986380d0]*/
+os_startfile_impl(PyObject *module, path_t *filepath,
+                  const Py_UNICODE *operation)
+/*[clinic end generated code: output=66dc311c94d50797 input=63950bf2986380d0]*/
 {
     HINSTANCE rc;
 
diff --git a/PC/clinic/winreg.c.h b/PC/clinic/winreg.c.h
index 1a535633552..a7385a6c693 100644
--- a/PC/clinic/winreg.c.h
+++ b/PC/clinic/winreg.c.h
@@ -137,14 +137,14 @@ PyDoc_STRVAR(winreg_ConnectRegistry__doc__,
     {"ConnectRegistry", (PyCFunction)(void(*)(void))winreg_ConnectRegistry, METH_FASTCALL, winreg_ConnectRegistry__doc__},
 
 static HKEY
-winreg_ConnectRegistry_impl(PyObject *module, Py_UNICODE *computer_name,
-                            HKEY key);
+winreg_ConnectRegistry_impl(PyObject *module,
+                            const Py_UNICODE *computer_name, HKEY key);
 
 static PyObject *
 winreg_ConnectRegistry(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    Py_UNICODE *computer_name;
+    const Py_UNICODE *computer_name;
     HKEY key;
     HKEY _return_value;
 
@@ -185,14 +185,14 @@ PyDoc_STRVAR(winreg_CreateKey__doc__,
     {"CreateKey", (PyCFunction)(void(*)(void))winreg_CreateKey, METH_FASTCALL, winreg_CreateKey__doc__},
 
 static HKEY
-winreg_CreateKey_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key);
+winreg_CreateKey_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key);
 
 static PyObject *
 winreg_CreateKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key;
     HKEY _return_value;
 
     if (!_PyArg_ParseStack(args, nargs, "O&Z:CreateKey",
@@ -238,8 +238,9 @@ PyDoc_STRVAR(winreg_CreateKeyEx__doc__,
     {"CreateKeyEx", (PyCFunction)(void(*)(void))winreg_CreateKeyEx, METH_FASTCALL|METH_KEYWORDS, winreg_CreateKeyEx__doc__},
 
 static HKEY
-winreg_CreateKeyEx_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
-                        int reserved, REGSAM access);
+winreg_CreateKeyEx_impl(PyObject *module, HKEY key,
+                        const Py_UNICODE *sub_key, int reserved,
+                        REGSAM access);
 
 static PyObject *
 winreg_CreateKeyEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
@@ -248,7 +249,7 @@ winreg_CreateKeyEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs, Py
     static const char * const _keywords[] = {"key", "sub_key", "reserved", "access", NULL};
     static _PyArg_Parser _parser = {"O&Z|ii:CreateKeyEx", _keywords, 0};
     HKEY key;
-    Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key;
     int reserved = 0;
     REGSAM access = KEY_WRITE;
     HKEY _return_value;
@@ -289,14 +290,14 @@ PyDoc_STRVAR(winreg_DeleteKey__doc__,
     {"DeleteKey", (PyCFunction)(void(*)(void))winreg_DeleteKey, METH_FASTCALL, winreg_DeleteKey__doc__},
 
 static PyObject *
-winreg_DeleteKey_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key);
+winreg_DeleteKey_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key);
 
 static PyObject *
 winreg_DeleteKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key;
 
     if (!_PyArg_ParseStack(args, nargs, "O&u:DeleteKey",
         clinic_HKEY_converter, &key, &sub_key)) {
@@ -337,8 +338,9 @@ PyDoc_STRVAR(winreg_DeleteKeyEx__doc__,
     {"DeleteKeyEx", (PyCFunction)(void(*)(void))winreg_DeleteKeyEx, METH_FASTCALL|METH_KEYWORDS, winreg_DeleteKeyEx__doc__},
 
 static PyObject *
-winreg_DeleteKeyEx_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
-                        REGSAM access, int reserved);
+winreg_DeleteKeyEx_impl(PyObject *module, HKEY key,
+                        const Py_UNICODE *sub_key, REGSAM access,
+                        int reserved);
 
 static PyObject *
 winreg_DeleteKeyEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
@@ -347,7 +349,7 @@ winreg_DeleteKeyEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs, Py
     static const char * const _keywords[] = {"key", "sub_key", "access", "reserved", NULL};
     static _PyArg_Parser _parser = {"O&u|ii:DeleteKeyEx", _keywords, 0};
     HKEY key;
-    Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key;
     REGSAM access = KEY_WOW64_64KEY;
     int reserved = 0;
 
@@ -376,14 +378,14 @@ PyDoc_STRVAR(winreg_DeleteValue__doc__,
     {"DeleteValue", (PyCFunction)(void(*)(void))winreg_DeleteValue, METH_FASTCALL, winreg_DeleteValue__doc__},
 
 static PyObject *
-winreg_DeleteValue_impl(PyObject *module, HKEY key, Py_UNICODE *value);
+winreg_DeleteValue_impl(PyObject *module, HKEY key, const Py_UNICODE *value);
 
 static PyObject *
 winreg_DeleteValue(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    Py_UNICODE *value;
+    const Py_UNICODE *value;
 
     if (!_PyArg_ParseStack(args, nargs, "O&Z:DeleteValue",
         clinic_HKEY_converter, &key, &value)) {
@@ -490,13 +492,14 @@ PyDoc_STRVAR(winreg_ExpandEnvironmentStrings__doc__,
     {"ExpandEnvironmentStrings", (PyCFunction)winreg_ExpandEnvironmentStrings, METH_O, winreg_ExpandEnvironmentStrings__doc__},
 
 static PyObject *
-winreg_ExpandEnvironmentStrings_impl(PyObject *module, Py_UNICODE *string);
+winreg_ExpandEnvironmentStrings_impl(PyObject *module,
+                                     const Py_UNICODE *string);
 
 static PyObject *
 winreg_ExpandEnvironmentStrings(PyObject *module, PyObject *arg)
 {
     PyObject *return_value = NULL;
-    Py_UNICODE *string;
+    const Py_UNICODE *string;
 
     if (!PyArg_Parse(arg, "u:ExpandEnvironmentStrings", &string)) {
         goto exit;
@@ -579,16 +582,16 @@ PyDoc_STRVAR(winreg_LoadKey__doc__,
     {"LoadKey", (PyCFunction)(void(*)(void))winreg_LoadKey, METH_FASTCALL, winreg_LoadKey__doc__},
 
 static PyObject *
-winreg_LoadKey_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
-                    Py_UNICODE *file_name);
+winreg_LoadKey_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key,
+                    const Py_UNICODE *file_name);
 
 static PyObject *
 winreg_LoadKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    Py_UNICODE *sub_key;
-    Py_UNICODE *file_name;
+    const Py_UNICODE *sub_key;
+    const Py_UNICODE *file_name;
 
     if (!_PyArg_ParseStack(args, nargs, "O&uu:LoadKey",
         clinic_HKEY_converter, &key, &sub_key, &file_name)) {
@@ -623,7 +626,7 @@ PyDoc_STRVAR(winreg_OpenKey__doc__,
     {"OpenKey", (PyCFunction)(void(*)(void))winreg_OpenKey, METH_FASTCALL|METH_KEYWORDS, winreg_OpenKey__doc__},
 
 static HKEY
-winreg_OpenKey_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
+winreg_OpenKey_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key,
                     int reserved, REGSAM access);
 
 static PyObject *
@@ -633,7 +636,7 @@ winreg_OpenKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
     static const char * const _keywords[] = {"key", "sub_key", "reserved", "access", NULL};
     static _PyArg_Parser _parser = {"O&Z|ii:OpenKey", _keywords, 0};
     HKEY key;
-    Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key;
     int reserved = 0;
     REGSAM access = KEY_READ;
     HKEY _return_value;
@@ -675,7 +678,7 @@ PyDoc_STRVAR(winreg_OpenKeyEx__doc__,
     {"OpenKeyEx", (PyCFunction)(void(*)(void))winreg_OpenKeyEx, METH_FASTCALL|METH_KEYWORDS, winreg_OpenKeyEx__doc__},
 
 static HKEY
-winreg_OpenKeyEx_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
+winreg_OpenKeyEx_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key,
                       int reserved, REGSAM access);
 
 static PyObject *
@@ -685,7 +688,7 @@ winreg_OpenKeyEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyOb
     static const char * const _keywords[] = {"key", "sub_key", "reserved", "access", NULL};
     static _PyArg_Parser _parser = {"O&Z|ii:OpenKeyEx", _keywords, 0};
     HKEY key;
-    Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key;
     int reserved = 0;
     REGSAM access = KEY_READ;
     HKEY _return_value;
@@ -764,14 +767,14 @@ PyDoc_STRVAR(winreg_QueryValue__doc__,
     {"QueryValue", (PyCFunction)(void(*)(void))winreg_QueryValue, METH_FASTCALL, winreg_QueryValue__doc__},
 
 static PyObject *
-winreg_QueryValue_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key);
+winreg_QueryValue_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key);
 
 static PyObject *
 winreg_QueryValue(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key;
 
     if (!_PyArg_ParseStack(args, nargs, "O&Z:QueryValue",
         clinic_HKEY_converter, &key, &sub_key)) {
@@ -803,14 +806,14 @@ PyDoc_STRVAR(winreg_QueryValueEx__doc__,
     {"QueryValueEx", (PyCFunction)(void(*)(void))winreg_QueryValueEx, METH_FASTCALL, winreg_QueryValueEx__doc__},
 
 static PyObject *
-winreg_QueryValueEx_impl(PyObject *module, HKEY key, Py_UNICODE *name);
+winreg_QueryValueEx_impl(PyObject *module, HKEY key, const Py_UNICODE *name);
 
 static PyObject *
 winreg_QueryValueEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    Py_UNICODE *name;
+    const Py_UNICODE *name;
 
     if (!_PyArg_ParseStack(args, nargs, "O&Z:QueryValueEx",
         clinic_HKEY_converter, &key, &name)) {
@@ -847,14 +850,14 @@ PyDoc_STRVAR(winreg_SaveKey__doc__,
     {"SaveKey", (PyCFunction)(void(*)(void))winreg_SaveKey, METH_FASTCALL, winreg_SaveKey__doc__},
 
 static PyObject *
-winreg_SaveKey_impl(PyObject *module, HKEY key, Py_UNICODE *file_name);
+winreg_SaveKey_impl(PyObject *module, HKEY key, const Py_UNICODE *file_name);
 
 static PyObject *
 winreg_SaveKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    Py_UNICODE *file_name;
+    const Py_UNICODE *file_name;
 
     if (!_PyArg_ParseStack(args, nargs, "O&u:SaveKey",
         clinic_HKEY_converter, &key, &file_name)) {
@@ -896,8 +899,8 @@ PyDoc_STRVAR(winreg_SetValue__doc__,
     {"SetValue", (PyCFunction)(void(*)(void))winreg_SetValue, METH_FASTCALL, winreg_SetValue__doc__},
 
 static PyObject *
-winreg_SetValue_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
-                     DWORD type, Py_UNICODE *value,
+winreg_SetValue_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key,
+                     DWORD type, const Py_UNICODE *value,
                      Py_ssize_clean_t value_length);
 
 static PyObject *
@@ -905,9 +908,9 @@ winreg_SetValue(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key;
     DWORD type;
-    Py_UNICODE *value;
+    const Py_UNICODE *value;
     Py_ssize_clean_t value_length;
 
     if (!_PyArg_ParseStack(args, nargs, "O&Zku#:SetValue",
@@ -967,15 +970,16 @@ PyDoc_STRVAR(winreg_SetValueEx__doc__,
     {"SetValueEx", (PyCFunction)(void(*)(void))winreg_SetValueEx, METH_FASTCALL, winreg_SetValueEx__doc__},
 
 static PyObject *
-winreg_SetValueEx_impl(PyObject *module, HKEY key, Py_UNICODE *value_name,
-                       PyObject *reserved, DWORD type, PyObject *value);
+winreg_SetValueEx_impl(PyObject *module, HKEY key,
+                       const Py_UNICODE *value_name, PyObject *reserved,
+                       DWORD type, PyObject *value);
 
 static PyObject *
 winreg_SetValueEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    Py_UNICODE *value_name;
+    const Py_UNICODE *value_name;
     PyObject *reserved;
     DWORD type;
     PyObject *value;
@@ -1091,4 +1095,4 @@ winreg_QueryReflectionKey(PyObject *module, PyObject *arg)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=45a9aec9f9258c0a input=a9049054013a1b77]*/
+/*[clinic end generated code: output=ff2cc1951ab1a56c input=a9049054013a1b77]*/
diff --git a/PC/winreg.c b/PC/winreg.c
index 4505c314d7b..8ed6be48f15 100644
--- a/PC/winreg.c
+++ b/PC/winreg.c
@@ -825,9 +825,9 @@ If the function fails, an OSError exception is raised.
 [clinic start generated code]*/
 
 static HKEY
-winreg_ConnectRegistry_impl(PyObject *module, Py_UNICODE *computer_name,
-                            HKEY key)
-/*[clinic end generated code: output=5ab79d02aa3167b4 input=5f98a891a347e68e]*/
+winreg_ConnectRegistry_impl(PyObject *module,
+                            const Py_UNICODE *computer_name, HKEY key)
+/*[clinic end generated code: output=cd4f70fb9ec901fb input=5f98a891a347e68e]*/
 {
     HKEY retKey;
     long rc;
@@ -862,8 +862,8 @@ If the function fails, an OSError exception is raised.
 [clinic start generated code]*/
 
 static HKEY
-winreg_CreateKey_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key)
-/*[clinic end generated code: output=9c81d4095527c927 input=3cdd1622488acea2]*/
+winreg_CreateKey_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key)
+/*[clinic end generated code: output=2af13910d56eae26 input=3cdd1622488acea2]*/
 {
     HKEY retKey;
     long rc;
@@ -901,9 +901,10 @@ If the function fails, an OSError exception is raised.
 [clinic start generated code]*/
 
 static HKEY
-winreg_CreateKeyEx_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
-                        int reserved, REGSAM access)
-/*[clinic end generated code: output=b9fce6dc5c4e39b1 input=42c2b03f98406b66]*/
+winreg_CreateKeyEx_impl(PyObject *module, HKEY key,
+                        const Py_UNICODE *sub_key, int reserved,
+                        REGSAM access)
+/*[clinic end generated code: output=643a70ad6a361a97 input=42c2b03f98406b66]*/
 {
     HKEY retKey;
     long rc;
@@ -936,8 +937,8 @@ is removed.  If the function fails, an OSError exception is raised.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_DeleteKey_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key)
-/*[clinic end generated code: output=7734b1e431991ae4 input=b31d225b935e4211]*/
+winreg_DeleteKey_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key)
+/*[clinic end generated code: output=d2652a84f70e0862 input=b31d225b935e4211]*/
 {
     long rc;
     rc = RegDeleteKeyW(key, sub_key );
@@ -971,9 +972,10 @@ On unsupported Windows versions, NotImplementedError is raised.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_DeleteKeyEx_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
-                        REGSAM access, int reserved)
-/*[clinic end generated code: output=01378d86ad3eb936 input=711d9d89e7ecbed7]*/
+winreg_DeleteKeyEx_impl(PyObject *module, HKEY key,
+                        const Py_UNICODE *sub_key, REGSAM access,
+                        int reserved)
+/*[clinic end generated code: output=52a1c8b374ebc003 input=711d9d89e7ecbed7]*/
 {
     HMODULE hMod;
     typedef LONG (WINAPI *RDKEFunc)(HKEY, const wchar_t*, REGSAM, int);
@@ -1013,8 +1015,8 @@ Removes a named value from a registry key.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_DeleteValue_impl(PyObject *module, HKEY key, Py_UNICODE *value)
-/*[clinic end generated code: output=67e7e9a514f84951 input=a78d3407a4197b21]*/
+winreg_DeleteValue_impl(PyObject *module, HKEY key, const Py_UNICODE *value)
+/*[clinic end generated code: output=56fa9d21f3a54371 input=a78d3407a4197b21]*/
 {
     long rc;
     Py_BEGIN_ALLOW_THREADS
@@ -1181,8 +1183,9 @@ Expand environment vars.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_ExpandEnvironmentStrings_impl(PyObject *module, Py_UNICODE *string)
-/*[clinic end generated code: output=cba46ac293a8af1a input=b2a9714d2b751aa6]*/
+winreg_ExpandEnvironmentStrings_impl(PyObject *module,
+                                     const Py_UNICODE *string)
+/*[clinic end generated code: output=8fa4e959747a7312 input=b2a9714d2b751aa6]*/
 {
     wchar_t *retValue = NULL;
     DWORD retValueSize;
@@ -1274,9 +1277,9 @@ tree.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_LoadKey_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
-                    Py_UNICODE *file_name)
-/*[clinic end generated code: output=87344005c5905cde input=e3b5b45ade311582]*/
+winreg_LoadKey_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key,
+                    const Py_UNICODE *file_name)
+/*[clinic end generated code: output=65f89f2548cb27c7 input=e3b5b45ade311582]*/
 {
     long rc;
 
@@ -1308,9 +1311,9 @@ If the function fails, an OSError exception is raised.
 [clinic start generated code]*/
 
 static HKEY
-winreg_OpenKey_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
+winreg_OpenKey_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key,
                     int reserved, REGSAM access)
-/*[clinic end generated code: output=a905f1b947f3ce85 input=098505ac36a9ae28]*/
+/*[clinic end generated code: output=8849bff2c30104ad input=098505ac36a9ae28]*/
 {
     HKEY retKey;
     long rc;
@@ -1335,9 +1338,9 @@ If the function fails, an OSError exception is raised.
 [clinic start generated code]*/
 
 static HKEY
-winreg_OpenKeyEx_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
+winreg_OpenKeyEx_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key,
                       int reserved, REGSAM access)
-/*[clinic end generated code: output=226042593b37e940 input=c6c4972af8622959]*/
+/*[clinic end generated code: output=81bc2bd684bc77ae input=c6c4972af8622959]*/
 {
     return winreg_OpenKey_impl(module, key, sub_key, reserved, access);
 }
@@ -1405,8 +1408,8 @@ completeness.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_QueryValue_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key)
-/*[clinic end generated code: output=2bb8d1e02c10d0b6 input=41cafbbf423b21d6]*/
+winreg_QueryValue_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key)
+/*[clinic end generated code: output=c655810ae50c63a9 input=41cafbbf423b21d6]*/
 {
     long rc;
     PyObject *retStr;
@@ -1472,8 +1475,8 @@ The return value is a tuple of the value and the type_id.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_QueryValueEx_impl(PyObject *module, HKEY key, Py_UNICODE *name)
-/*[clinic end generated code: output=5b4fa3e33d6d3e8f input=cf366cada4836891]*/
+winreg_QueryValueEx_impl(PyObject *module, HKEY key, const Py_UNICODE *name)
+/*[clinic end generated code: output=f1b85b1c3d887ec7 input=cf366cada4836891]*/
 {
     long rc;
     BYTE *retBuf, *tmp;
@@ -1545,8 +1548,8 @@ to the API.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_SaveKey_impl(PyObject *module, HKEY key, Py_UNICODE *file_name)
-/*[clinic end generated code: output=1dda1502bd4c30d8 input=da735241f91ac7a2]*/
+winreg_SaveKey_impl(PyObject *module, HKEY key, const Py_UNICODE *file_name)
+/*[clinic end generated code: output=ca94b835c88f112b input=da735241f91ac7a2]*/
 {
     LPSECURITY_ATTRIBUTES pSA = NULL;
 
@@ -1591,10 +1594,10 @@ KEY_SET_VALUE access.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_SetValue_impl(PyObject *module, HKEY key, Py_UNICODE *sub_key,
-                     DWORD type, Py_UNICODE *value,
+winreg_SetValue_impl(PyObject *module, HKEY key, const Py_UNICODE *sub_key,
+                     DWORD type, const Py_UNICODE *value,
                      Py_ssize_clean_t value_length)
-/*[clinic end generated code: output=1e31931174820631 input=2cd2adab79339c53]*/
+/*[clinic end generated code: output=686bedb1cbb4367b input=2cd2adab79339c53]*/
 {
     long rc;
 
@@ -1657,9 +1660,10 @@ the configuration registry to help the registry perform efficiently.
 [clinic start generated code]*/
 
 static PyObject *
-winreg_SetValueEx_impl(PyObject *module, HKEY key, Py_UNICODE *value_name,
-                       PyObject *reserved, DWORD type, PyObject *value)
-/*[clinic end generated code: output=c88c8426b6c00ec7 input=900a9e3990bfb196]*/
+winreg_SetValueEx_impl(PyObject *module, HKEY key,
+                       const Py_UNICODE *value_name, PyObject *reserved,
+                       DWORD type, PyObject *value)
+/*[clinic end generated code: output=811b769a66ae11b7 input=900a9e3990bfb196]*/
 {
     BYTE *data;
     DWORD len;
diff --git a/Tools/clinic/clinic.py b/Tools/clinic/clinic.py
index 2df80714407..1adabb95cc9 100755
--- a/Tools/clinic/clinic.py
+++ b/Tools/clinic/clinic.py
@@ -2858,7 +2858,7 @@ class unicode_converter(CConverter):
 @add_legacy_c_converter('Z', accept={str, NoneType})
 @add_legacy_c_converter('Z#', accept={str, NoneType}, zeroes=True)
 class Py_UNICODE_converter(CConverter):
-    type = 'Py_UNICODE *'
+    type = 'const Py_UNICODE *'
     default_type = (str, Null, NoneType)
     format_unit = 'u'