diff --git a/Lib/test/clinic.test b/Lib/test/clinic.test
index f9c55e2..0d84d5e 100644
--- a/Lib/test/clinic.test
+++ b/Lib/test/clinic.test
@@ -92,7 +92,7 @@
 [clinic start generated code]*/
 
 PyDoc_STRVAR(test_objects_converter__doc__,
-"test_objects_converter($module, a, b=None, /)\n"
+"test_objects_converter($module, a, b=<unrepresentable>, /)\n"
 "--\n"
 "\n");
 
@@ -126,7 +126,7 @@
 
 static PyObject *
 test_objects_converter_impl(PyObject *module, PyObject *a, PyObject *b)
-/*[clinic end generated code: output=58009c0e42b4834e input=4cbb3d9edd2a36f3]*/
+/*[clinic end generated code: output=0e461f38d3b2bd08 input=4cbb3d9edd2a36f3]*/
 
 
 /*[clinic input]
@@ -1718,8 +1718,8 @@
 [clinic start generated code]*/
 
 PyDoc_STRVAR(test_str_converter__doc__,
-"test_str_converter($module, a=None, b=\'ab\', c=\'cd\', d=\'cef\', e=\'gh\',\n"
-"                   f=\'ij\', g=\'kl\', h=\'mn\', /)\n"
+"test_str_converter($module, a=<unrepresentable>, b=\'ab\', c=\'cd\',\n"
+"                   d=\'cef\', e=\'gh\', f=\'ij\', g=\'kl\', h=\'mn\', /)\n"
 "--\n"
 "\n");
 
@@ -1765,7 +1765,7 @@
                         const char *f, Py_ssize_clean_t f_length,
                         const char *g, Py_ssize_clean_t g_length,
                         const char *h, Py_ssize_clean_t h_length)
-/*[clinic end generated code: output=8415d82c56154307 input=8afe9da8185cd38c]*/
+/*[clinic end generated code: output=ad868ad94a488e32 input=8afe9da8185cd38c]*/
 
 
 /*[clinic input]
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 7148dfa..9d28d5a 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -2269,8 +2269,8 @@
         test_callable(d.dump)
 
         # static method
-        test_callable(str.maketrans)
-        test_callable('abc'.maketrans)
+        test_callable(bytes.maketrans)
+        test_callable(b'abc'.maketrans)
 
         # class method
         test_callable(dict.fromkeys)
diff --git a/Misc/NEWS.d/next/Library/2019-06-09-22-25-03.bpo-37206.2WBg4q.rst b/Misc/NEWS.d/next/Library/2019-06-09-22-25-03.bpo-37206.2WBg4q.rst
new file mode 100644
index 0000000..2c6c682
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2019-06-09-22-25-03.bpo-37206.2WBg4q.rst
@@ -0,0 +1,2 @@
+Default values which cannot be represented as Python objects no longer
+improperly represented as ``None`` in function signatures.
diff --git a/Modules/_codecsmodule.c b/Modules/_codecsmodule.c
index 90b3e37..a8ffb69 100644
--- a/Modules/_codecsmodule.c
+++ b/Modules/_codecsmodule.c
@@ -171,14 +171,14 @@
 /*[clinic input]
 _codecs.escape_decode
     data: Py_buffer(accept={str, buffer})
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_escape_decode_impl(PyObject *module, Py_buffer *data,
                            const char *errors)
-/*[clinic end generated code: output=505200ba8056979a input=0018edfd99db714d]*/
+/*[clinic end generated code: output=505200ba8056979a input=77298a561c90bd82]*/
 {
     PyObject *decoded = PyBytes_DecodeEscape(data->buf, data->len,
                                              errors, 0, NULL);
@@ -188,14 +188,14 @@
 /*[clinic input]
 _codecs.escape_encode
     data: object(subclass_of='&PyBytes_Type')
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_escape_encode_impl(PyObject *module, PyObject *data,
                            const char *errors)
-/*[clinic end generated code: output=4af1d477834bab34 input=da9ded00992f32f2]*/
+/*[clinic end generated code: output=4af1d477834bab34 input=8f4b144799a94245]*/
 {
     Py_ssize_t size;
     Py_ssize_t newsize;
@@ -252,7 +252,7 @@
 /*[clinic input]
 _codecs.utf_7_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -260,7 +260,7 @@
 static PyObject *
 _codecs_utf_7_decode_impl(PyObject *module, Py_buffer *data,
                           const char *errors, int final)
-/*[clinic end generated code: output=0cd3a944a32a4089 input=2d94a5a1f170c8ae]*/
+/*[clinic end generated code: output=0cd3a944a32a4089 input=22c395d357815d26]*/
 {
     Py_ssize_t consumed = data->len;
     PyObject *decoded = PyUnicode_DecodeUTF7Stateful(data->buf, data->len,
@@ -272,7 +272,7 @@
 /*[clinic input]
 _codecs.utf_8_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -280,7 +280,7 @@
 static PyObject *
 _codecs_utf_8_decode_impl(PyObject *module, Py_buffer *data,
                           const char *errors, int final)
-/*[clinic end generated code: output=10f74dec8d9bb8bf input=1ea6c21492e8bcbe]*/
+/*[clinic end generated code: output=10f74dec8d9bb8bf input=f611b3867352ba59]*/
 {
     Py_ssize_t consumed = data->len;
     PyObject *decoded = PyUnicode_DecodeUTF8Stateful(data->buf, data->len,
@@ -292,7 +292,7 @@
 /*[clinic input]
 _codecs.utf_16_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -300,7 +300,7 @@
 static PyObject *
 _codecs_utf_16_decode_impl(PyObject *module, Py_buffer *data,
                            const char *errors, int final)
-/*[clinic end generated code: output=783b442abcbcc2d0 input=2ba128c28ea0bb40]*/
+/*[clinic end generated code: output=783b442abcbcc2d0 input=191d360bd7309180]*/
 {
     int byteorder = 0;
     /* This is overwritten unless final is true. */
@@ -314,7 +314,7 @@
 /*[clinic input]
 _codecs.utf_16_le_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -322,7 +322,7 @@
 static PyObject *
 _codecs_utf_16_le_decode_impl(PyObject *module, Py_buffer *data,
                               const char *errors, int final)
-/*[clinic end generated code: output=899b9e6364379dcd input=43aeb8b0461cace5]*/
+/*[clinic end generated code: output=899b9e6364379dcd input=c6904fdc27fb4724]*/
 {
     int byteorder = -1;
     /* This is overwritten unless final is true. */
@@ -336,7 +336,7 @@
 /*[clinic input]
 _codecs.utf_16_be_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -344,7 +344,7 @@
 static PyObject *
 _codecs_utf_16_be_decode_impl(PyObject *module, Py_buffer *data,
                               const char *errors, int final)
-/*[clinic end generated code: output=49f6465ea07669c8 input=339e554c804f34b2]*/
+/*[clinic end generated code: output=49f6465ea07669c8 input=e49012400974649b]*/
 {
     int byteorder = 1;
     /* This is overwritten unless final is true. */
@@ -365,7 +365,7 @@
 /*[clinic input]
 _codecs.utf_16_ex_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     byteorder: int = 0
     final: bool(accept={int}) = False
     /
@@ -374,7 +374,7 @@
 static PyObject *
 _codecs_utf_16_ex_decode_impl(PyObject *module, Py_buffer *data,
                               const char *errors, int byteorder, int final)
-/*[clinic end generated code: output=0f385f251ecc1988 input=3201aeddb9636889]*/
+/*[clinic end generated code: output=0f385f251ecc1988 input=5a9c19f2e6b6cf0e]*/
 {
     /* This is overwritten unless final is true. */
     Py_ssize_t consumed = data->len;
@@ -390,7 +390,7 @@
 /*[clinic input]
 _codecs.utf_32_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -398,7 +398,7 @@
 static PyObject *
 _codecs_utf_32_decode_impl(PyObject *module, Py_buffer *data,
                            const char *errors, int final)
-/*[clinic end generated code: output=2fc961807f7b145f input=155a5c673a4e2514]*/
+/*[clinic end generated code: output=2fc961807f7b145f input=fd7193965627eb58]*/
 {
     int byteorder = 0;
     /* This is overwritten unless final is true. */
@@ -412,7 +412,7 @@
 /*[clinic input]
 _codecs.utf_32_le_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -420,7 +420,7 @@
 static PyObject *
 _codecs_utf_32_le_decode_impl(PyObject *module, Py_buffer *data,
                               const char *errors, int final)
-/*[clinic end generated code: output=ec8f46b67a94f3e6 input=7baf061069e92d3b]*/
+/*[clinic end generated code: output=ec8f46b67a94f3e6 input=9078ec70acfe7613]*/
 {
     int byteorder = -1;
     /* This is overwritten unless final is true. */
@@ -434,7 +434,7 @@
 /*[clinic input]
 _codecs.utf_32_be_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -442,7 +442,7 @@
 static PyObject *
 _codecs_utf_32_be_decode_impl(PyObject *module, Py_buffer *data,
                               const char *errors, int final)
-/*[clinic end generated code: output=ff82bae862c92c4e input=b182026300dae595]*/
+/*[clinic end generated code: output=ff82bae862c92c4e input=f1ae1bbbb86648ff]*/
 {
     int byteorder = 1;
     /* This is overwritten unless final is true. */
@@ -463,7 +463,7 @@
 /*[clinic input]
 _codecs.utf_32_ex_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     byteorder: int = 0
     final: bool(accept={int}) = False
     /
@@ -472,7 +472,7 @@
 static PyObject *
 _codecs_utf_32_ex_decode_impl(PyObject *module, Py_buffer *data,
                               const char *errors, int byteorder, int final)
-/*[clinic end generated code: output=6bfb177dceaf4848 input=7b9c2cb819fb237a]*/
+/*[clinic end generated code: output=6bfb177dceaf4848 input=e46a73bc859d0bd0]*/
 {
     Py_ssize_t consumed = data->len;
     PyObject *decoded = PyUnicode_DecodeUTF32Stateful(data->buf, data->len,
@@ -486,14 +486,14 @@
 /*[clinic input]
 _codecs.unicode_escape_decode
     data: Py_buffer(accept={str, buffer})
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_unicode_escape_decode_impl(PyObject *module, Py_buffer *data,
                                    const char *errors)
-/*[clinic end generated code: output=3ca3c917176b82ab input=49fd27d06813a7f5]*/
+/*[clinic end generated code: output=3ca3c917176b82ab input=8328081a3a569bd6]*/
 {
     PyObject *decoded = PyUnicode_DecodeUnicodeEscape(data->buf, data->len,
                                                       errors);
@@ -503,14 +503,14 @@
 /*[clinic input]
 _codecs.raw_unicode_escape_decode
     data: Py_buffer(accept={str, buffer})
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_raw_unicode_escape_decode_impl(PyObject *module, Py_buffer *data,
                                        const char *errors)
-/*[clinic end generated code: output=c98eeb56028070a6 input=770903a211434ebc]*/
+/*[clinic end generated code: output=c98eeb56028070a6 input=d2f5159ce3b3392f]*/
 {
     PyObject *decoded = PyUnicode_DecodeRawUnicodeEscape(data->buf, data->len,
                                                          errors);
@@ -520,14 +520,14 @@
 /*[clinic input]
 _codecs.latin_1_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_latin_1_decode_impl(PyObject *module, Py_buffer *data,
                             const char *errors)
-/*[clinic end generated code: output=07f3dfa3f72c7d8f input=5cad0f1759c618ec]*/
+/*[clinic end generated code: output=07f3dfa3f72c7d8f input=76ca58fd6dcd08c7]*/
 {
     PyObject *decoded = PyUnicode_DecodeLatin1(data->buf, data->len, errors);
     return codec_tuple(decoded, data->len);
@@ -536,14 +536,14 @@
 /*[clinic input]
 _codecs.ascii_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_ascii_decode_impl(PyObject *module, Py_buffer *data,
                           const char *errors)
-/*[clinic end generated code: output=2627d72058d42429 input=ad1106f64037bd16]*/
+/*[clinic end generated code: output=2627d72058d42429 input=e428a267a04b4481]*/
 {
     PyObject *decoded = PyUnicode_DecodeASCII(data->buf, data->len, errors);
     return codec_tuple(decoded, data->len);
@@ -552,15 +552,15 @@
 /*[clinic input]
 _codecs.charmap_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
-    mapping: object = NULL
+    errors: str(accept={str, NoneType}) = None
+    mapping: object = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_charmap_decode_impl(PyObject *module, Py_buffer *data,
                             const char *errors, PyObject *mapping)
-/*[clinic end generated code: output=2c335b09778cf895 input=19712ca35c5a80e2]*/
+/*[clinic end generated code: output=2c335b09778cf895 input=15b69df43458eb40]*/
 {
     PyObject *decoded;
 
@@ -576,7 +576,7 @@
 /*[clinic input]
 _codecs.mbcs_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -584,7 +584,7 @@
 static PyObject *
 _codecs_mbcs_decode_impl(PyObject *module, Py_buffer *data,
                          const char *errors, int final)
-/*[clinic end generated code: output=39b65b8598938c4b input=b5f2fe568f311297]*/
+/*[clinic end generated code: output=39b65b8598938c4b input=1c1d50f08fa53789]*/
 {
     Py_ssize_t consumed = data->len;
     PyObject *decoded = PyUnicode_DecodeMBCSStateful(data->buf, data->len,
@@ -595,7 +595,7 @@
 /*[clinic input]
 _codecs.oem_decode
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -603,7 +603,7 @@
 static PyObject *
 _codecs_oem_decode_impl(PyObject *module, Py_buffer *data,
                         const char *errors, int final)
-/*[clinic end generated code: output=da1617612f3fcad8 input=278709bcfd374a9c]*/
+/*[clinic end generated code: output=da1617612f3fcad8 input=81b67cba811022e5]*/
 {
     Py_ssize_t consumed = data->len;
     PyObject *decoded = PyUnicode_DecodeCodePageStateful(CP_OEMCP,
@@ -615,7 +615,7 @@
 _codecs.code_page_decode
     codepage: int
     data: Py_buffer
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     final: bool(accept={int}) = False
     /
 [clinic start generated code]*/
@@ -623,7 +623,7 @@
 static PyObject *
 _codecs_code_page_decode_impl(PyObject *module, int codepage,
                               Py_buffer *data, const char *errors, int final)
-/*[clinic end generated code: output=53008ea967da3fff input=51f6169021c68dd5]*/
+/*[clinic end generated code: output=53008ea967da3fff input=c5f58d036cb63575]*/
 {
     Py_ssize_t consumed = data->len;
     PyObject *decoded = PyUnicode_DecodeCodePageStateful(codepage,
@@ -640,14 +640,14 @@
 /*[clinic input]
 _codecs.readbuffer_encode
     data: Py_buffer(accept={str, buffer})
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_readbuffer_encode_impl(PyObject *module, Py_buffer *data,
                                const char *errors)
-/*[clinic end generated code: output=c645ea7cdb3d6e86 input=b7c322b89d4ab923]*/
+/*[clinic end generated code: output=c645ea7cdb3d6e86 input=aa10cfdf252455c5]*/
 {
     PyObject *result = PyBytes_FromStringAndSize(data->buf, data->len);
     return codec_tuple(result, data->len);
@@ -656,14 +656,14 @@
 /*[clinic input]
 _codecs.utf_7_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_utf_7_encode_impl(PyObject *module, PyObject *str,
                           const char *errors)
-/*[clinic end generated code: output=0feda21ffc921bc8 input=d1a47579e79cbe15]*/
+/*[clinic end generated code: output=0feda21ffc921bc8 input=2546dbbb3fa53114]*/
 {
     return codec_tuple(_PyUnicode_EncodeUTF7(str, 0, 0, errors),
                        PyUnicode_GET_LENGTH(str));
@@ -672,14 +672,14 @@
 /*[clinic input]
 _codecs.utf_8_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_utf_8_encode_impl(PyObject *module, PyObject *str,
                           const char *errors)
-/*[clinic end generated code: output=02bf47332b9c796c input=42e3ba73c4392eef]*/
+/*[clinic end generated code: output=02bf47332b9c796c input=a3e71ae01c3f93f3]*/
 {
     return codec_tuple(_PyUnicode_AsUTF8String(str, errors),
                        PyUnicode_GET_LENGTH(str));
@@ -695,7 +695,7 @@
 /*[clinic input]
 _codecs.utf_16_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     byteorder: int = 0
     /
 [clinic start generated code]*/
@@ -703,7 +703,7 @@
 static PyObject *
 _codecs_utf_16_encode_impl(PyObject *module, PyObject *str,
                            const char *errors, int byteorder)
-/*[clinic end generated code: output=c654e13efa2e64e4 input=ff46416b04edb944]*/
+/*[clinic end generated code: output=c654e13efa2e64e4 input=68cdc2eb8338555d]*/
 {
     return codec_tuple(_PyUnicode_EncodeUTF16(str, errors, byteorder),
                        PyUnicode_GET_LENGTH(str));
@@ -712,14 +712,14 @@
 /*[clinic input]
 _codecs.utf_16_le_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_utf_16_le_encode_impl(PyObject *module, PyObject *str,
                               const char *errors)
-/*[clinic end generated code: output=431b01e55f2d4995 input=cb385455ea8f2fe0]*/
+/*[clinic end generated code: output=431b01e55f2d4995 input=83d042706eed6798]*/
 {
     return codec_tuple(_PyUnicode_EncodeUTF16(str, errors, -1),
                        PyUnicode_GET_LENGTH(str));
@@ -728,14 +728,14 @@
 /*[clinic input]
 _codecs.utf_16_be_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_utf_16_be_encode_impl(PyObject *module, PyObject *str,
                               const char *errors)
-/*[clinic end generated code: output=96886a6fd54dcae3 input=9119997066bdaefd]*/
+/*[clinic end generated code: output=96886a6fd54dcae3 input=6f1e9e623b03071b]*/
 {
     return codec_tuple(_PyUnicode_EncodeUTF16(str, errors, +1),
                        PyUnicode_GET_LENGTH(str));
@@ -751,7 +751,7 @@
 /*[clinic input]
 _codecs.utf_32_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     byteorder: int = 0
     /
 [clinic start generated code]*/
@@ -759,7 +759,7 @@
 static PyObject *
 _codecs_utf_32_encode_impl(PyObject *module, PyObject *str,
                            const char *errors, int byteorder)
-/*[clinic end generated code: output=5c760da0c09a8b83 input=c5e77da82fbe5c2a]*/
+/*[clinic end generated code: output=5c760da0c09a8b83 input=8ec4c64d983bc52b]*/
 {
     return codec_tuple(_PyUnicode_EncodeUTF32(str, errors, byteorder),
                        PyUnicode_GET_LENGTH(str));
@@ -768,14 +768,14 @@
 /*[clinic input]
 _codecs.utf_32_le_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_utf_32_le_encode_impl(PyObject *module, PyObject *str,
                               const char *errors)
-/*[clinic end generated code: output=b65cd176de8e36d6 input=9993b25fe0877848]*/
+/*[clinic end generated code: output=b65cd176de8e36d6 input=f0918d41de3eb1b1]*/
 {
     return codec_tuple(_PyUnicode_EncodeUTF32(str, errors, -1),
                        PyUnicode_GET_LENGTH(str));
@@ -784,14 +784,14 @@
 /*[clinic input]
 _codecs.utf_32_be_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_utf_32_be_encode_impl(PyObject *module, PyObject *str,
                               const char *errors)
-/*[clinic end generated code: output=1d9e71a9358709e9 input=d3e0ccaa02920431]*/
+/*[clinic end generated code: output=1d9e71a9358709e9 input=967a99a95748b557]*/
 {
     return codec_tuple(_PyUnicode_EncodeUTF32(str, errors, +1),
                        PyUnicode_GET_LENGTH(str));
@@ -800,14 +800,14 @@
 /*[clinic input]
 _codecs.unicode_escape_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_unicode_escape_encode_impl(PyObject *module, PyObject *str,
                                    const char *errors)
-/*[clinic end generated code: output=66271b30bc4f7a3c input=65d9eefca65b455a]*/
+/*[clinic end generated code: output=66271b30bc4f7a3c input=8c4de07597054e33]*/
 {
     return codec_tuple(PyUnicode_AsUnicodeEscapeString(str),
                        PyUnicode_GET_LENGTH(str));
@@ -816,14 +816,14 @@
 /*[clinic input]
 _codecs.raw_unicode_escape_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_raw_unicode_escape_encode_impl(PyObject *module, PyObject *str,
                                        const char *errors)
-/*[clinic end generated code: output=a66a806ed01c830a input=5aa33e4a133391ab]*/
+/*[clinic end generated code: output=a66a806ed01c830a input=4aa6f280d78e4574]*/
 {
     return codec_tuple(PyUnicode_AsRawUnicodeEscapeString(str),
                        PyUnicode_GET_LENGTH(str));
@@ -832,14 +832,14 @@
 /*[clinic input]
 _codecs.latin_1_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_latin_1_encode_impl(PyObject *module, PyObject *str,
                             const char *errors)
-/*[clinic end generated code: output=2c28c83a27884e08 input=30b11c9e49a65150]*/
+/*[clinic end generated code: output=2c28c83a27884e08 input=ec3ef74bf85c5c5d]*/
 {
     return codec_tuple(_PyUnicode_AsLatin1String(str, errors),
                        PyUnicode_GET_LENGTH(str));
@@ -848,14 +848,14 @@
 /*[clinic input]
 _codecs.ascii_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_ascii_encode_impl(PyObject *module, PyObject *str,
                           const char *errors)
-/*[clinic end generated code: output=b5e035182d33befc input=843a1d268e6dfa8e]*/
+/*[clinic end generated code: output=b5e035182d33befc input=93e6e602838bd3de]*/
 {
     return codec_tuple(_PyUnicode_AsASCIIString(str, errors),
                        PyUnicode_GET_LENGTH(str));
@@ -864,15 +864,15 @@
 /*[clinic input]
 _codecs.charmap_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
-    mapping: object = NULL
+    errors: str(accept={str, NoneType}) = None
+    mapping: object = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_charmap_encode_impl(PyObject *module, PyObject *str,
                             const char *errors, PyObject *mapping)
-/*[clinic end generated code: output=047476f48495a9e9 input=0752cde07a6d6d00]*/
+/*[clinic end generated code: output=047476f48495a9e9 input=2a98feae73dadce8]*/
 {
     if (mapping == Py_None)
         mapping = NULL;
@@ -899,13 +899,13 @@
 /*[clinic input]
 _codecs.mbcs_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_mbcs_encode_impl(PyObject *module, PyObject *str, const char *errors)
-/*[clinic end generated code: output=76e2e170c966c080 input=de471e0815947553]*/
+/*[clinic end generated code: output=76e2e170c966c080 input=2e932fc289ea5a5b]*/
 {
     return codec_tuple(PyUnicode_EncodeCodePage(CP_ACP, str, errors),
                        PyUnicode_GET_LENGTH(str));
@@ -914,13 +914,13 @@
 /*[clinic input]
 _codecs.oem_encode
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_oem_encode_impl(PyObject *module, PyObject *str, const char *errors)
-/*[clinic end generated code: output=65d5982c737de649 input=3fc5f0028aad3cda]*/
+/*[clinic end generated code: output=65d5982c737de649 input=9eac86dc21eb14f2]*/
 {
     return codec_tuple(PyUnicode_EncodeCodePage(CP_OEMCP, str, errors),
         PyUnicode_GET_LENGTH(str));
@@ -930,14 +930,14 @@
 _codecs.code_page_encode
     code_page: int
     str: unicode
-    errors: str(accept={str, NoneType}) = NULL
+    errors: str(accept={str, NoneType}) = None
     /
 [clinic start generated code]*/
 
 static PyObject *
 _codecs_code_page_encode_impl(PyObject *module, int code_page, PyObject *str,
                               const char *errors)
-/*[clinic end generated code: output=45673f6085657a9e input=786421ae617d680b]*/
+/*[clinic end generated code: output=45673f6085657a9e input=7d18a33bc8cd0f94]*/
 {
     return codec_tuple(PyUnicode_EncodeCodePage(code_page, str, errors),
                        PyUnicode_GET_LENGTH(str));
diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
index c66f794..98fd1f3 100644
--- a/Modules/_cursesmodule.c
+++ b/Modules/_cursesmodule.c
@@ -3202,7 +3202,7 @@
 /*[clinic input]
 _curses.setupterm
 
-    term: str(accept={str, NoneType}) = NULL
+    term: str(accept={str, NoneType}) = None
         Terminal name.
         If omitted, the value of the TERM environment variable will be used.
     fd: int = -1
@@ -3214,7 +3214,7 @@
 
 static PyObject *
 _curses_setupterm_impl(PyObject *module, const char *term, int fd)
-/*[clinic end generated code: output=4584e587350f2848 input=8ac5f78ec6268be3]*/
+/*[clinic end generated code: output=4584e587350f2848 input=4511472766af0c12]*/
 {
     int err;
 
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index b88e8a1..9050144 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -2408,10 +2408,10 @@
 /*[clinic input]
 _elementtree.TreeBuilder.__init__
 
-    element_factory: object = NULL
+    element_factory: object = None
     *
-    comment_factory: object = NULL
-    pi_factory: object = NULL
+    comment_factory: object = None
+    pi_factory: object = None
     insert_comments: bool = False
     insert_pis: bool = False
 
@@ -2423,16 +2423,16 @@
                                        PyObject *comment_factory,
                                        PyObject *pi_factory,
                                        int insert_comments, int insert_pis)
-/*[clinic end generated code: output=8571d4dcadfdf952 input=1f967b5c245e0a71]*/
+/*[clinic end generated code: output=8571d4dcadfdf952 input=ae98a94df20b5cc3]*/
 {
-    if (element_factory && element_factory != Py_None) {
+    if (element_factory != Py_None) {
         Py_INCREF(element_factory);
         Py_XSETREF(self->element_factory, element_factory);
     } else {
         Py_CLEAR(self->element_factory);
     }
 
-    if (!comment_factory || comment_factory == Py_None) {
+    if (comment_factory == Py_None) {
         elementtreestate *st = ET_STATE_GLOBAL;
         comment_factory = st->comment_factory;
     }
@@ -2445,7 +2445,7 @@
         self->insert_comments = 0;
     }
 
-    if (!pi_factory || pi_factory == Py_None) {
+    if (pi_factory == Py_None) {
         elementtreestate *st = ET_STATE_GLOBAL;
         pi_factory = st->pi_factory;
     }
@@ -3651,14 +3651,14 @@
 
     *
     target: object = NULL
-    encoding: str(accept={str, NoneType}) = NULL
+    encoding: str(accept={str, NoneType}) = None
 
 [clinic start generated code]*/
 
 static int
 _elementtree_XMLParser___init___impl(XMLParserObject *self, PyObject *target,
                                      const char *encoding)
-/*[clinic end generated code: output=3ae45ec6cdf344e4 input=96288fcba916cfce]*/
+/*[clinic end generated code: output=3ae45ec6cdf344e4 input=53e35a829ae043e8]*/
 {
     self->entity = PyDict_New();
     if (!self->entity)
diff --git a/Modules/_hashopenssl.c b/Modules/_hashopenssl.c
index 29ebec7..aa91be2 100644
--- a/Modules/_hashopenssl.c
+++ b/Modules/_hashopenssl.c
@@ -584,7 +584,7 @@
 _hashlib.new as EVP_new
 
     name as name_obj: object
-    string as data_obj: object(py_default="b''") = NULL
+    string as data_obj: object(c_default="NULL") = b''
     *
     usedforsecurity: bool = True
 
@@ -599,7 +599,7 @@
 static PyObject *
 EVP_new_impl(PyObject *module, PyObject *name_obj, PyObject *data_obj,
              int usedforsecurity)
-/*[clinic end generated code: output=ddd5053f92dffe90 input=e9ac115d80962ddf]*/
+/*[clinic end generated code: output=ddd5053f92dffe90 input=c24554d0337be1b0]*/
 {
     Py_buffer view = { 0 };
     PyObject *ret_obj;
diff --git a/Modules/_io/_iomodule.c b/Modules/_io/_iomodule.c
index 162b288..b4cc894 100644
--- a/Modules/_io/_iomodule.c
+++ b/Modules/_io/_iomodule.c
@@ -103,9 +103,9 @@
     file: object
     mode: str = "r"
     buffering: int = -1
-    encoding: str(accept={str, NoneType}) = NULL
-    errors: str(accept={str, NoneType}) = NULL
-    newline: str(accept={str, NoneType}) = NULL
+    encoding: str(accept={str, NoneType}) = None
+    errors: str(accept={str, NoneType}) = None
+    newline: str(accept={str, NoneType}) = None
     closefd: bool(accept={int}) = True
     opener: object = None
 
@@ -233,7 +233,7 @@
 _io_open_impl(PyObject *module, PyObject *file, const char *mode,
               int buffering, const char *encoding, const char *errors,
               const char *newline, int closefd, PyObject *opener)
-/*[clinic end generated code: output=aefafc4ce2b46dc0 input=03da2940c8a65871]*/
+/*[clinic end generated code: output=aefafc4ce2b46dc0 input=7295902222e6b311]*/
 {
     unsigned i;
 
diff --git a/Modules/_io/clinic/fileio.c.h b/Modules/_io/clinic/fileio.c.h
index 64addde..53e7067 100644
--- a/Modules/_io/clinic/fileio.c.h
+++ b/Modules/_io/clinic/fileio.c.h
@@ -408,7 +408,7 @@
 _io_FileIO_truncate(fileio *self, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    PyObject *posobj = NULL;
+    PyObject *posobj = Py_None;
 
     if (!_PyArg_CheckPositional("truncate", nargs, 0, 1)) {
         goto exit;
@@ -447,4 +447,4 @@
 #ifndef _IO_FILEIO_TRUNCATE_METHODDEF
     #define _IO_FILEIO_TRUNCATE_METHODDEF
 #endif /* !defined(_IO_FILEIO_TRUNCATE_METHODDEF) */
-/*[clinic end generated code: output=a7e9cca3613660fb input=a9049054013a1b77]*/
+/*[clinic end generated code: output=e7682d0a3264d284 input=a9049054013a1b77]*/
diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index e4cbbfa..fd32b19 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -979,7 +979,7 @@
 #ifdef HAVE_FTRUNCATE
 /*[clinic input]
 _io.FileIO.truncate
-    size as posobj: object = NULL
+    size as posobj: object = None
     /
 
 Truncate the file to at most size bytes and return the truncated size.
@@ -990,7 +990,7 @@
 
 static PyObject *
 _io_FileIO_truncate_impl(fileio *self, PyObject *posobj)
-/*[clinic end generated code: output=e49ca7a916c176fa input=9026af44686b7318]*/
+/*[clinic end generated code: output=e49ca7a916c176fa input=b0ac133939823875]*/
 {
     Py_off_t pos;
     int ret;
@@ -1002,7 +1002,7 @@
     if (!self->writable)
         return err_mode("writing");
 
-    if (posobj == Py_None || posobj == NULL) {
+    if (posobj == Py_None) {
         /* Get the current position. */
         posobj = portable_lseek(self, NULL, 1);
         if (posobj == NULL)
diff --git a/Modules/_io/textio.c b/Modules/_io/textio.c
index 1db8d94..5ebeb02 100644
--- a/Modules/_io/textio.c
+++ b/Modules/_io/textio.c
@@ -1031,9 +1031,9 @@
 /*[clinic input]
 _io.TextIOWrapper.__init__
     buffer: object
-    encoding: str(accept={str, NoneType}) = NULL
+    encoding: str(accept={str, NoneType}) = None
     errors: object = None
-    newline: str(accept={str, NoneType}) = NULL
+    newline: str(accept={str, NoneType}) = None
     line_buffering: bool(accept={int}) = False
     write_through: bool(accept={int}) = False
 
@@ -1072,7 +1072,7 @@
                                 const char *encoding, PyObject *errors,
                                 const char *newline, int line_buffering,
                                 int write_through)
-/*[clinic end generated code: output=72267c0c01032ed2 input=1c5dd5d78bfcc675]*/
+/*[clinic end generated code: output=72267c0c01032ed2 input=77d8696d1a1f460b]*/
 {
     PyObject *raw, *codec_info = NULL;
     _PyIO_State *state = NULL;
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index 9e82d14..7370be5 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -1142,7 +1142,7 @@
 {
     long proto;
 
-    if (protocol == NULL || protocol == Py_None) {
+    if (protocol == Py_None) {
         proto = DEFAULT_PROTOCOL;
     }
     else {
@@ -4638,9 +4638,9 @@
 _pickle.Pickler.__init__
 
   file: object
-  protocol: object = NULL
+  protocol: object = None
   fix_imports: bool = True
-  buffer_callback: object = NULL
+  buffer_callback: object = None
 
 This takes a binary file for writing a pickle data stream.
 
@@ -4678,7 +4678,7 @@
 _pickle_Pickler___init___impl(PicklerObject *self, PyObject *file,
                               PyObject *protocol, int fix_imports,
                               PyObject *buffer_callback)
-/*[clinic end generated code: output=0abedc50590d259b input=9a43a1c50ab91652]*/
+/*[clinic end generated code: output=0abedc50590d259b input=bb886e00443a7811]*/
 {
     _Py_IDENTIFIER(persistent_id);
     _Py_IDENTIFIER(dispatch_table);
@@ -7200,7 +7200,7 @@
   fix_imports: bool = True
   encoding: str = 'ASCII'
   errors: str = 'strict'
-  buffers: object = NULL
+  buffers: object(c_default="NULL") = ()
 
 This takes a binary file for reading a pickle data stream.
 
@@ -7228,7 +7228,7 @@
 _pickle_Unpickler___init___impl(UnpicklerObject *self, PyObject *file,
                                 int fix_imports, const char *encoding,
                                 const char *errors, PyObject *buffers)
-/*[clinic end generated code: output=09f0192649ea3f85 input=da4b62d9edb68700]*/
+/*[clinic end generated code: output=09f0192649ea3f85 input=ca4c1faea9553121]*/
 {
     _Py_IDENTIFIER(persistent_load);
 
@@ -7620,10 +7620,10 @@
 
   obj: object
   file: object
-  protocol: object = NULL
+  protocol: object = None
   *
   fix_imports: bool = True
-  buffer_callback: object = NULL
+  buffer_callback: object = None
 
 Write a pickled representation of obj to the open file object file.
 
@@ -7658,7 +7658,7 @@
 _pickle_dump_impl(PyObject *module, PyObject *obj, PyObject *file,
                   PyObject *protocol, int fix_imports,
                   PyObject *buffer_callback)
-/*[clinic end generated code: output=706186dba996490c input=2f035f02cc0f9547]*/
+/*[clinic end generated code: output=706186dba996490c input=cfdcaf573ed6e46c]*/
 {
     PicklerObject *pickler = _Pickler_New();
 
@@ -7693,10 +7693,10 @@
 _pickle.dumps
 
   obj: object
-  protocol: object = NULL
+  protocol: object = None
   *
   fix_imports: bool = True
-  buffer_callback: object = NULL
+  buffer_callback: object = None
 
 Return the pickled representation of the object as a bytes object.
 
@@ -7722,7 +7722,7 @@
 static PyObject *
 _pickle_dumps_impl(PyObject *module, PyObject *obj, PyObject *protocol,
                    int fix_imports, PyObject *buffer_callback)
-/*[clinic end generated code: output=fbab0093a5580fdf input=001f167df711b9f1]*/
+/*[clinic end generated code: output=fbab0093a5580fdf input=9f334d535ff7194f]*/
 {
     PyObject *result;
     PicklerObject *pickler = _Pickler_New();
@@ -7757,7 +7757,7 @@
   fix_imports: bool = True
   encoding: str = 'ASCII'
   errors: str = 'strict'
-  buffers: object = NULL
+  buffers: object(c_default="NULL") = ()
 
 Read and return an object from the pickle data stored in a file.
 
@@ -7788,7 +7788,7 @@
 _pickle_load_impl(PyObject *module, PyObject *file, int fix_imports,
                   const char *encoding, const char *errors,
                   PyObject *buffers)
-/*[clinic end generated code: output=250452d141c23e76 input=29fae982fe778156]*/
+/*[clinic end generated code: output=250452d141c23e76 input=46c7c31c92f4f371]*/
 {
     PyObject *result;
     UnpicklerObject *unpickler = _Unpickler_New();
@@ -7825,7 +7825,7 @@
   fix_imports: bool = True
   encoding: str = 'ASCII'
   errors: str = 'strict'
-  buffers: object = NULL
+  buffers: object(c_default="NULL") = ()
 
 Read and return an object from the given pickle data.
 
@@ -7847,7 +7847,7 @@
 _pickle_loads_impl(PyObject *module, PyObject *data, int fix_imports,
                    const char *encoding, const char *errors,
                    PyObject *buffers)
-/*[clinic end generated code: output=82ac1e6b588e6d02 input=c6004393f8276867]*/
+/*[clinic end generated code: output=82ac1e6b588e6d02 input=9c2ab6a0960185ea]*/
 {
     PyObject *result;
     UnpicklerObject *unpickler = _Unpickler_New();
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index 64060c6..6f1f9c8 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -3883,15 +3883,15 @@
 /*[clinic input]
 _ssl._SSLContext.load_cert_chain
     certfile: object
-    keyfile: object = NULL
-    password: object = NULL
+    keyfile: object = None
+    password: object = None
 
 [clinic start generated code]*/
 
 static PyObject *
 _ssl__SSLContext_load_cert_chain_impl(PySSLContext *self, PyObject *certfile,
                                       PyObject *keyfile, PyObject *password)
-/*[clinic end generated code: output=9480bc1c380e2095 input=7cf9ac673cbee6fc]*/
+/*[clinic end generated code: output=9480bc1c380e2095 input=30bc7e967ea01a58]*/
 {
     PyObject *certfile_bytes = NULL, *keyfile_bytes = NULL;
     pem_password_cb *orig_passwd_cb = SSL_CTX_get_default_passwd_cb(self->ctx);
@@ -3917,7 +3917,7 @@
         }
         goto error;
     }
-    if (password && password != Py_None) {
+    if (password != Py_None) {
         if (PyCallable_Check(password)) {
             pw_info.callable = password;
         } else if (!_pwinfo_set(&pw_info, password,
@@ -4075,9 +4075,9 @@
 
 /*[clinic input]
 _ssl._SSLContext.load_verify_locations
-    cafile: object = NULL
-    capath: object = NULL
-    cadata: object = NULL
+    cafile: object = None
+    capath: object = None
+    cadata: object = None
 
 [clinic start generated code]*/
 
@@ -4086,7 +4086,7 @@
                                             PyObject *cafile,
                                             PyObject *capath,
                                             PyObject *cadata)
-/*[clinic end generated code: output=454c7e41230ca551 input=997f1fb3a784ef88]*/
+/*[clinic end generated code: output=454c7e41230ca551 input=42ecfe258233e194]*/
 {
     PyObject *cafile_bytes = NULL, *capath_bytes = NULL;
     const char *cafile_buf = NULL, *capath_buf = NULL;
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 036f9b6..94d5b64 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -3121,8 +3121,8 @@
 /*[clinic input]
 _tkinter.create
 
-    screenName: str(accept={str, NoneType}) = NULL
-    baseName: str = NULL
+    screenName: str(accept={str, NoneType}) = None
+    baseName: str = ""
     className: str = "Tk"
     interactive: bool(accept={int}) = False
     wantobjects: bool(accept={int}) = False
@@ -3130,7 +3130,7 @@
         if false, then Tk_Init() doesn't get called
     sync: bool(accept={int}) = False
         if true, then pass -sync to wish
-    use: str(accept={str, NoneType}) = NULL
+    use: str(accept={str, NoneType}) = None
         if not None, then pass -use to wish
     /
 
@@ -3141,7 +3141,7 @@
                      const char *baseName, const char *className,
                      int interactive, int wantobjects, int wantTk, int sync,
                      const char *use)
-/*[clinic end generated code: output=e3315607648e6bb4 input=431907c134c80085]*/
+/*[clinic end generated code: output=e3315607648e6bb4 input=da9b17ee7358d862]*/
 {
     /* XXX baseName is not used anymore;
      * try getting rid of it. */
diff --git a/Modules/cjkcodecs/multibytecodec.c b/Modules/cjkcodecs/multibytecodec.c
index 4de6787..56d0076 100644
--- a/Modules/cjkcodecs/multibytecodec.c
+++ b/Modules/cjkcodecs/multibytecodec.c
@@ -538,7 +538,7 @@
 _multibytecodec.MultibyteCodec.encode
 
   input: object
-  errors: str(accept={str, NoneType}) = NULL
+  errors: str(accept={str, NoneType}) = None
 
 Return an encoded string version of `input'.
 
@@ -552,7 +552,7 @@
 _multibytecodec_MultibyteCodec_encode_impl(MultibyteCodecObject *self,
                                            PyObject *input,
                                            const char *errors)
-/*[clinic end generated code: output=7b26652045ba56a9 input=05f6ced3c8dd0582]*/
+/*[clinic end generated code: output=7b26652045ba56a9 input=606d0e128a577bae]*/
 {
     MultibyteCodec_State state;
     PyObject *errorcb, *r, *ucvt;
@@ -607,7 +607,7 @@
 _multibytecodec.MultibyteCodec.decode
 
   input: Py_buffer
-  errors: str(accept={str, NoneType}) = NULL
+  errors: str(accept={str, NoneType}) = None
 
 Decodes 'input'.
 
@@ -621,7 +621,7 @@
 _multibytecodec_MultibyteCodec_decode_impl(MultibyteCodecObject *self,
                                            Py_buffer *input,
                                            const char *errors)
-/*[clinic end generated code: output=ff419f65bad6cc77 input=a7d45f87f75e5e02]*/
+/*[clinic end generated code: output=ff419f65bad6cc77 input=e0c78fc7ab190def]*/
 {
     MultibyteCodec_State state;
     MultibyteDecodeBuffer buf;
diff --git a/Modules/clinic/_asynciomodule.c.h b/Modules/clinic/_asynciomodule.c.h
index b9daee6..17eb773 100644
--- a/Modules/clinic/_asynciomodule.c.h
+++ b/Modules/clinic/_asynciomodule.c.h
@@ -119,7 +119,7 @@
     {"set_exception", (PyCFunction)_asyncio_Future_set_exception, METH_O, _asyncio_Future_set_exception__doc__},
 
 PyDoc_STRVAR(_asyncio_Future_add_done_callback__doc__,
-"add_done_callback($self, fn, /, *, context=None)\n"
+"add_done_callback($self, fn, /, *, context=<unrepresentable>)\n"
 "--\n"
 "\n"
 "Add a callback to be run when the future becomes done.\n"
@@ -832,4 +832,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=51c50219f6a0863a input=a9049054013a1b77]*/
+/*[clinic end generated code: output=585ba1f8de5b4103 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_codecsmodule.c.h b/Modules/clinic/_codecsmodule.c.h
index be1d2f7..772c8ca 100644
--- a/Modules/clinic/_codecsmodule.c.h
+++ b/Modules/clinic/_codecsmodule.c.h
@@ -1434,7 +1434,7 @@
     PyObject *return_value = NULL;
     Py_buffer data = {NULL, NULL};
     const char *errors = NULL;
-    PyObject *mapping = NULL;
+    PyObject *mapping = Py_None;
 
     if (!_PyArg_CheckPositional("charmap_decode", nargs, 1, 3)) {
         goto exit;
@@ -2542,7 +2542,7 @@
     PyObject *return_value = NULL;
     PyObject *str;
     const char *errors = NULL;
-    PyObject *mapping = NULL;
+    PyObject *mapping = Py_None;
 
     if (!_PyArg_CheckPositional("charmap_encode", nargs, 1, 3)) {
         goto exit;
@@ -2922,4 +2922,4 @@
 #ifndef _CODECS_CODE_PAGE_ENCODE_METHODDEF
     #define _CODECS_CODE_PAGE_ENCODE_METHODDEF
 #endif /* !defined(_CODECS_CODE_PAGE_ENCODE_METHODDEF) */
-/*[clinic end generated code: output=59726a305e4ec24a input=a9049054013a1b77]*/
+/*[clinic end generated code: output=51b42d170889524c input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_elementtree.c.h b/Modules/clinic/_elementtree.c.h
index a58ad73..a184b0f 100644
--- a/Modules/clinic/_elementtree.c.h
+++ b/Modules/clinic/_elementtree.c.h
@@ -597,9 +597,9 @@
     PyObject * const *fastargs;
     Py_ssize_t nargs = PyTuple_GET_SIZE(args);
     Py_ssize_t noptargs = nargs + (kwargs ? PyDict_GET_SIZE(kwargs) : 0) - 0;
-    PyObject *element_factory = NULL;
-    PyObject *comment_factory = NULL;
-    PyObject *pi_factory = NULL;
+    PyObject *element_factory = Py_None;
+    PyObject *comment_factory = Py_None;
+    PyObject *pi_factory = Py_None;
     int insert_comments = 0;
     int insert_pis = 0;
 
@@ -916,4 +916,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=f5dbf9b4a095d310 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=bee26d0735a3fddc input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_pickle.c.h b/Modules/clinic/_pickle.c.h
index b92daa7..9da3f11 100644
--- a/Modules/clinic/_pickle.c.h
+++ b/Modules/clinic/_pickle.c.h
@@ -112,9 +112,9 @@
     Py_ssize_t nargs = PyTuple_GET_SIZE(args);
     Py_ssize_t noptargs = nargs + (kwargs ? PyDict_GET_SIZE(kwargs) : 0) - 1;
     PyObject *file;
-    PyObject *protocol = NULL;
+    PyObject *protocol = Py_None;
     int fix_imports = 1;
-    PyObject *buffer_callback = NULL;
+    PyObject *buffer_callback = Py_None;
 
     fastargs = _PyArg_UnpackKeywords(_PyTuple_CAST(args)->ob_item, nargs, kwargs, NULL, &_parser, 1, 4, 0, argsbuf);
     if (!fastargs) {
@@ -292,7 +292,7 @@
 
 PyDoc_STRVAR(_pickle_Unpickler___init____doc__,
 "Unpickler(file, *, fix_imports=True, encoding=\'ASCII\', errors=\'strict\',\n"
-"          buffers=None)\n"
+"          buffers=())\n"
 "--\n"
 "\n"
 "This takes a binary file for reading a pickle data stream.\n"
@@ -502,9 +502,9 @@
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 2;
     PyObject *obj;
     PyObject *file;
-    PyObject *protocol = NULL;
+    PyObject *protocol = Py_None;
     int fix_imports = 1;
-    PyObject *buffer_callback = NULL;
+    PyObject *buffer_callback = Py_None;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 2, 3, 0, argsbuf);
     if (!args) {
@@ -582,9 +582,9 @@
     PyObject *argsbuf[4];
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 1;
     PyObject *obj;
-    PyObject *protocol = NULL;
+    PyObject *protocol = Py_None;
     int fix_imports = 1;
-    PyObject *buffer_callback = NULL;
+    PyObject *buffer_callback = Py_None;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 2, 0, argsbuf);
     if (!args) {
@@ -623,7 +623,7 @@
 
 PyDoc_STRVAR(_pickle_load__doc__,
 "load($module, /, file, *, fix_imports=True, encoding=\'ASCII\',\n"
-"     errors=\'strict\', buffers=None)\n"
+"     errors=\'strict\', buffers=())\n"
 "--\n"
 "\n"
 "Read and return an object from the pickle data stored in a file.\n"
@@ -735,7 +735,7 @@
 
 PyDoc_STRVAR(_pickle_loads__doc__,
 "loads($module, /, data, *, fix_imports=True, encoding=\'ASCII\',\n"
-"      errors=\'strict\', buffers=None)\n"
+"      errors=\'strict\', buffers=())\n"
 "--\n"
 "\n"
 "Read and return an object from the given pickle data.\n"
@@ -835,4 +835,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=17f6a76ebd94325d input=a9049054013a1b77]*/
+/*[clinic end generated code: output=de075ec48d4ee0e1 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_ssl.c.h b/Modules/clinic/_ssl.c.h
index 25769a2..ce8669a 100644
--- a/Modules/clinic/_ssl.c.h
+++ b/Modules/clinic/_ssl.c.h
@@ -571,8 +571,8 @@
     PyObject *argsbuf[3];
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 1;
     PyObject *certfile;
-    PyObject *keyfile = NULL;
-    PyObject *password = NULL;
+    PyObject *keyfile = Py_None;
+    PyObject *password = Py_None;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 3, 0, argsbuf);
     if (!args) {
@@ -618,9 +618,9 @@
     static _PyArg_Parser _parser = {NULL, _keywords, "load_verify_locations", 0};
     PyObject *argsbuf[3];
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 0;
-    PyObject *cafile = NULL;
-    PyObject *capath = NULL;
-    PyObject *cadata = NULL;
+    PyObject *cafile = Py_None;
+    PyObject *capath = Py_None;
+    PyObject *cadata = Py_None;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 0, 3, 0, argsbuf);
     if (!args) {
@@ -1482,4 +1482,4 @@
 #ifndef _SSL_ENUM_CRLS_METHODDEF
     #define _SSL_ENUM_CRLS_METHODDEF
 #endif /* !defined(_SSL_ENUM_CRLS_METHODDEF) */
-/*[clinic end generated code: output=aa4947067c3fef2d input=a9049054013a1b77]*/
+/*[clinic end generated code: output=a4aeb3f92a091c64 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_tkinter.c.h b/Modules/clinic/_tkinter.c.h
index 4870e9b..73c3fae 100644
--- a/Modules/clinic/_tkinter.c.h
+++ b/Modules/clinic/_tkinter.c.h
@@ -674,7 +674,7 @@
     {"_flatten", (PyCFunction)_tkinter__flatten, METH_O, _tkinter__flatten__doc__},
 
 PyDoc_STRVAR(_tkinter_create__doc__,
-"create($module, screenName=None, baseName=None, className=\'Tk\',\n"
+"create($module, screenName=None, baseName=\'\', className=\'Tk\',\n"
 "       interactive=False, wantobjects=False, wantTk=True, sync=False,\n"
 "       use=None, /)\n"
 "--\n"
@@ -702,7 +702,7 @@
 {
     PyObject *return_value = NULL;
     const char *screenName = NULL;
-    const char *baseName = NULL;
+    const char *baseName = "";
     const char *className = "Tk";
     int interactive = 0;
     int wantobjects = 0;
@@ -912,4 +912,4 @@
 #ifndef _TKINTER_TKAPP_DELETEFILEHANDLER_METHODDEF
     #define _TKINTER_TKAPP_DELETEFILEHANDLER_METHODDEF
 #endif /* !defined(_TKINTER_TKAPP_DELETEFILEHANDLER_METHODDEF) */
-/*[clinic end generated code: output=da0115c470aac1c0 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=492b8b833fe54bc9 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/binascii.c.h b/Modules/clinic/binascii.c.h
index e18d407..82942f0 100644
--- a/Modules/clinic/binascii.c.h
+++ b/Modules/clinic/binascii.c.h
@@ -432,7 +432,7 @@
 }
 
 PyDoc_STRVAR(binascii_b2a_hex__doc__,
-"b2a_hex($module, /, data, sep=None, bytes_per_sep=1)\n"
+"b2a_hex($module, /, data, sep=<unrepresentable>, bytes_per_sep=1)\n"
 "--\n"
 "\n"
 "Hexadecimal representation of binary data.\n"
@@ -515,7 +515,7 @@
 }
 
 PyDoc_STRVAR(binascii_hexlify__doc__,
-"hexlify($module, /, data, sep=None, bytes_per_sep=1)\n"
+"hexlify($module, /, data, sep=<unrepresentable>, bytes_per_sep=1)\n"
 "--\n"
 "\n"
 "Hexadecimal representation of binary data.\n"
@@ -801,4 +801,4 @@
 
     return return_value;
 }
-/*[clinic end generated code: output=e13bd02ac40496f0 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=ec26d03c2007eaac input=a9049054013a1b77]*/
diff --git a/Modules/clinic/cmathmodule.c.h b/Modules/clinic/cmathmodule.c.h
index 3350987..81a8437 100644
--- a/Modules/clinic/cmathmodule.c.h
+++ b/Modules/clinic/cmathmodule.c.h
@@ -648,10 +648,10 @@
 }
 
 PyDoc_STRVAR(cmath_log__doc__,
-"log($module, x, y_obj=None, /)\n"
+"log($module, z, base=<unrepresentable>, /)\n"
 "--\n"
 "\n"
-"The logarithm of z to the given base.\n"
+"log(z[, base]) -> the logarithm of z to the given base.\n"
 "\n"
 "If the base not specified, returns the natural logarithm (base e) of z.");
 
@@ -968,4 +968,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=3ab228947d1709cc input=a9049054013a1b77]*/
+/*[clinic end generated code: output=3edc4484b10ae752 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/posixmodule.c.h b/Modules/clinic/posixmodule.c.h
index cb4ef59..b21d174 100644
--- a/Modules/clinic/posixmodule.c.h
+++ b/Modules/clinic/posixmodule.c.h
@@ -1971,8 +1971,8 @@
 #endif /* defined(HAVE_UNAME) */
 
 PyDoc_STRVAR(os_utime__doc__,
-"utime($module, /, path, times=None, *, ns=None, dir_fd=None,\n"
-"      follow_symlinks=True)\n"
+"utime($module, /, path, times=None, *, ns=<unrepresentable>,\n"
+"      dir_fd=None, follow_symlinks=True)\n"
 "--\n"
 "\n"
 "Set the access and modified time of path.\n"
@@ -2015,7 +2015,7 @@
     PyObject *argsbuf[5];
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 1;
     path_t path = PATH_T_INITIALIZE("utime", "path", 0, PATH_UTIME_HAVE_FD);
-    PyObject *times = NULL;
+    PyObject *times = Py_None;
     PyObject *ns = NULL;
     int dir_fd = DEFAULT_DIR_FD;
     int follow_symlinks = 1;
@@ -2208,8 +2208,8 @@
 
 PyDoc_STRVAR(os_posix_spawn__doc__,
 "posix_spawn($module, path, argv, env, /, *, file_actions=(),\n"
-"            setpgroup=None, resetids=False, setsid=False,\n"
-"            setsigmask=(), setsigdef=(), scheduler=None)\n"
+"            setpgroup=<unrepresentable>, resetids=False, setsid=False,\n"
+"            setsigmask=(), setsigdef=(), scheduler=<unrepresentable>)\n"
 "--\n"
 "\n"
 "Execute the program specified by path in a new process.\n"
@@ -2345,8 +2345,8 @@
 
 PyDoc_STRVAR(os_posix_spawnp__doc__,
 "posix_spawnp($module, path, argv, env, /, *, file_actions=(),\n"
-"             setpgroup=None, resetids=False, setsid=False,\n"
-"             setsigmask=(), setsigdef=(), scheduler=None)\n"
+"             setpgroup=<unrepresentable>, resetids=False, setsid=False,\n"
+"             setsigmask=(), setsigdef=(), scheduler=<unrepresentable>)\n"
 "--\n"
 "\n"
 "Execute the program specified by path in a new process.\n"
@@ -2598,8 +2598,9 @@
 #if defined(HAVE_FORK)
 
 PyDoc_STRVAR(os_register_at_fork__doc__,
-"register_at_fork($module, /, *, before=None, after_in_child=None,\n"
-"                 after_in_parent=None)\n"
+"register_at_fork($module, /, *, before=<unrepresentable>,\n"
+"                 after_in_child=<unrepresentable>,\n"
+"                 after_in_parent=<unrepresentable>)\n"
 "--\n"
 "\n"
 "Register callables to be called when forking a new process.\n"
@@ -6854,11 +6855,9 @@
 #if defined(MS_WINDOWS)
 
 PyDoc_STRVAR(os_startfile__doc__,
-"startfile($module, /, filepath, operation=None)\n"
+"startfile($module, /, filepath, operation=<unrepresentable>)\n"
 "--\n"
 "\n"
-"startfile(filepath [, operation])\n"
-"\n"
 "Start a file with its associated application.\n"
 "\n"
 "When \"operation\" is not specified or \"open\", this acts like\n"
@@ -8724,4 +8723,4 @@
 #ifndef OS__REMOVE_DLL_DIRECTORY_METHODDEF
     #define OS__REMOVE_DLL_DIRECTORY_METHODDEF
 #endif /* !defined(OS__REMOVE_DLL_DIRECTORY_METHODDEF) */
-/*[clinic end generated code: output=3c5cb675b0d09145 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=113d9fbdd18a62f5 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/pyexpat.c.h b/Modules/clinic/pyexpat.c.h
index 41ab536..ee5907c 100644
--- a/Modules/clinic/pyexpat.c.h
+++ b/Modules/clinic/pyexpat.c.h
@@ -133,7 +133,8 @@
 }
 
 PyDoc_STRVAR(pyexpat_xmlparser_ExternalEntityParserCreate__doc__,
-"ExternalEntityParserCreate($self, context, encoding=None, /)\n"
+"ExternalEntityParserCreate($self, context, encoding=<unrepresentable>,\n"
+"                           /)\n"
 "--\n"
 "\n"
 "Create a parser for parsing an external entity based on the information passed to the ExternalEntityRefHandler.");
@@ -280,7 +281,7 @@
 
 PyDoc_STRVAR(pyexpat_ParserCreate__doc__,
 "ParserCreate($module, /, encoding=None, namespace_separator=None,\n"
-"             intern=None)\n"
+"             intern=<unrepresentable>)\n"
 "--\n"
 "\n"
 "Return a new XML parser object.");
@@ -401,4 +402,4 @@
 #ifndef PYEXPAT_XMLPARSER_USEFOREIGNDTD_METHODDEF
     #define PYEXPAT_XMLPARSER_USEFOREIGNDTD_METHODDEF
 #endif /* !defined(PYEXPAT_XMLPARSER_USEFOREIGNDTD_METHODDEF) */
-/*[clinic end generated code: output=133a4105d508ebec input=a9049054013a1b77]*/
+/*[clinic end generated code: output=68ce25024280af41 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/unicodedata.c.h b/Modules/clinic/unicodedata.c.h
index 77e4f22..4251db2 100644
--- a/Modules/clinic/unicodedata.c.h
+++ b/Modules/clinic/unicodedata.c.h
@@ -3,7 +3,7 @@
 [clinic start generated code]*/
 
 PyDoc_STRVAR(unicodedata_UCD_decimal__doc__,
-"decimal($self, chr, default=None, /)\n"
+"decimal($self, chr, default=<unrepresentable>, /)\n"
 "--\n"
 "\n"
 "Converts a Unicode character into its equivalent decimal value.\n"
@@ -53,7 +53,7 @@
 }
 
 PyDoc_STRVAR(unicodedata_UCD_digit__doc__,
-"digit($self, chr, default=None, /)\n"
+"digit($self, chr, default=<unrepresentable>, /)\n"
 "--\n"
 "\n"
 "Converts a Unicode character into its equivalent digit value.\n"
@@ -102,7 +102,7 @@
 }
 
 PyDoc_STRVAR(unicodedata_UCD_numeric__doc__,
-"numeric($self, chr, default=None, /)\n"
+"numeric($self, chr, default=<unrepresentable>, /)\n"
 "--\n"
 "\n"
 "Converts a Unicode character into its equivalent numeric value.\n"
@@ -481,7 +481,7 @@
 }
 
 PyDoc_STRVAR(unicodedata_UCD_name__doc__,
-"name($self, chr, default=None, /)\n"
+"name($self, chr, default=<unrepresentable>, /)\n"
 "--\n"
 "\n"
 "Returns the name assigned to the character chr as a string.\n"
@@ -559,4 +559,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=3238f76814fb48d1 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=10c23477dbe8a202 input=a9049054013a1b77]*/
diff --git a/Modules/cmathmodule.c b/Modules/cmathmodule.c
index b421f04..02c09bb 100644
--- a/Modules/cmathmodule.c
+++ b/Modules/cmathmodule.c
@@ -944,18 +944,18 @@
 /*[clinic input]
 cmath.log
 
-    x: Py_complex
-    y_obj: object = NULL
+    z as x: Py_complex
+    base as y_obj: object = NULL
     /
 
-The logarithm of z to the given base.
+log(z[, base]) -> the logarithm of z to the given base.
 
 If the base not specified, returns the natural logarithm (base e) of z.
 [clinic start generated code]*/
 
 static PyObject *
 cmath_log_impl(PyObject *module, Py_complex x, PyObject *y_obj)
-/*[clinic end generated code: output=4effdb7d258e0d94 input=ee0e823a7c6e68ea]*/
+/*[clinic end generated code: output=4effdb7d258e0d94 input=230ed3a71ecd000a]*/
 {
     Py_complex y;
 
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index e71d4b2..c60d0c5 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -4736,7 +4736,7 @@
 os.utime
 
     path: path_t(allow_fd='PATH_UTIME_HAVE_FD')
-    times: object = NULL
+    times: object = None
     *
     ns: object = NULL
     dir_fd: dir_fd(requires='futimensat') = None
@@ -4773,7 +4773,7 @@
 static PyObject *
 os_utime_impl(PyObject *module, path_t *path, PyObject *times, PyObject *ns,
               int dir_fd, int follow_symlinks)
-/*[clinic end generated code: output=cfcac69d027b82cf input=081cdc54ca685385]*/
+/*[clinic end generated code: output=cfcac69d027b82cf input=2fbd62a2f228f8f4]*/
 {
 #ifdef MS_WINDOWS
     HANDLE hFile;
@@ -4786,14 +4786,14 @@
 
     memset(&utime, 0, sizeof(utime_t));
 
-    if (times && (times != Py_None) && ns) {
+    if (times != Py_None && ns) {
         PyErr_SetString(PyExc_ValueError,
                      "utime: you may specify either 'times'"
                      " or 'ns' but not both");
         return NULL;
     }
 
-    if (times && (times != Py_None)) {
+    if (times != Py_None) {
         time_t a_sec, m_sec;
         long a_nsec, m_nsec;
         if (!PyTuple_CheckExact(times) || (PyTuple_Size(times) != 2)) {
@@ -11579,8 +11579,6 @@
     filepath: path_t
     operation: Py_UNICODE = NULL
 
-startfile(filepath [, operation])
-
 Start a file with its associated application.
 
 When "operation" is not specified or "open", this acts like
@@ -11602,7 +11600,7 @@
 static PyObject *
 os_startfile_impl(PyObject *module, path_t *filepath,
                   const Py_UNICODE *operation)
-/*[clinic end generated code: output=66dc311c94d50797 input=63950bf2986380d0]*/
+/*[clinic end generated code: output=66dc311c94d50797 input=c940888a5390f039]*/
 {
     HINSTANCE rc;
 
diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index 5d284cd..d912335 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -1503,8 +1503,8 @@
 /*[clinic input]
 pyexpat.ParserCreate
 
-    encoding: str(accept={str, NoneType}) = NULL
-    namespace_separator: str(accept={str, NoneType}) = NULL
+    encoding: str(accept={str, NoneType}) = None
+    namespace_separator: str(accept={str, NoneType}) = None
     intern: object = NULL
 
 Return a new XML parser object.
@@ -1513,7 +1513,7 @@
 static PyObject *
 pyexpat_ParserCreate_impl(PyObject *module, const char *encoding,
                           const char *namespace_separator, PyObject *intern)
-/*[clinic end generated code: output=295c0cf01ab1146c input=23d29704acad385d]*/
+/*[clinic end generated code: output=295c0cf01ab1146c input=e8da8e8d7122cb5d]*/
 {
     PyObject *result;
     int intern_decref = 0;
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 4b2a77b..7df9344 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -1948,7 +1948,7 @@
 Py_LOCAL_INLINE(PyObject *)
 do_argstrip(PyBytesObject *self, int striptype, PyObject *bytes)
 {
-    if (bytes != NULL && bytes != Py_None) {
+    if (bytes != Py_None) {
         return do_xstrip(self, striptype, bytes);
     }
     return do_strip(self, striptype);
diff --git a/Objects/clinic/bytearrayobject.c.h b/Objects/clinic/bytearrayobject.c.h
index ad8ed7e..0557707 100644
--- a/Objects/clinic/bytearrayobject.c.h
+++ b/Objects/clinic/bytearrayobject.c.h
@@ -868,7 +868,7 @@
 }
 
 PyDoc_STRVAR(bytearray_hex__doc__,
-"hex($self, /, sep=None, bytes_per_sep=1)\n"
+"hex($self, /, sep=<unrepresentable>, bytes_per_sep=1)\n"
 "--\n"
 "\n"
 "Create a str of hexadecimal numbers from a bytearray object.\n"
@@ -1011,4 +1011,4 @@
 {
     return bytearray_sizeof_impl(self);
 }
-/*[clinic end generated code: output=09df354d3374dfb2 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=508dce79cf2dffcc input=a9049054013a1b77]*/
diff --git a/Objects/clinic/bytesobject.c.h b/Objects/clinic/bytesobject.c.h
index 7e2ce1a..22024ab 100644
--- a/Objects/clinic/bytesobject.c.h
+++ b/Objects/clinic/bytesobject.c.h
@@ -688,7 +688,7 @@
 }
 
 PyDoc_STRVAR(bytes_hex__doc__,
-"hex($self, /, sep=None, bytes_per_sep=1)\n"
+"hex($self, /, sep=<unrepresentable>, bytes_per_sep=1)\n"
 "--\n"
 "\n"
 "Create a str of hexadecimal numbers from a bytes object.\n"
@@ -755,4 +755,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=dbed3c3ff6faa382 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=ca60dfccf8d51e88 input=a9049054013a1b77]*/
diff --git a/Objects/clinic/dictobject.c.h b/Objects/clinic/dictobject.c.h
index b87244d..7395e3b 100644
--- a/Objects/clinic/dictobject.c.h
+++ b/Objects/clinic/dictobject.c.h
@@ -117,10 +117,10 @@
 }
 
 PyDoc_STRVAR(dict_pop__doc__,
-"pop($self, key, default=None, /)\n"
+"pop($self, key, default=<unrepresentable>, /)\n"
 "--\n"
 "\n"
-"Remove specified key and return the corresponding value.\n"
+"D.pop(k[,d]) -> v, remove specified key and return the corresponding value.\n"
 "\n"
 "If key is not found, default is returned if given, otherwise KeyError is raised");
 
@@ -190,4 +190,4 @@
 {
     return dict___reversed___impl(self);
 }
-/*[clinic end generated code: output=0fd5cafc61a51d3c input=a9049054013a1b77]*/
+/*[clinic end generated code: output=4d98145508da8fa3 input=a9049054013a1b77]*/
diff --git a/Objects/clinic/floatobject.c.h b/Objects/clinic/floatobject.c.h
index 6515d11..b684ba0 100644
--- a/Objects/clinic/floatobject.c.h
+++ b/Objects/clinic/floatobject.c.h
@@ -56,7 +56,7 @@
 float___round__(PyObject *self, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    PyObject *o_ndigits = NULL;
+    PyObject *o_ndigits = Py_None;
 
     if (!_PyArg_CheckPositional("__round__", nargs, 0, 1)) {
         goto exit;
@@ -351,4 +351,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=cc8098eb73f1a64c input=a9049054013a1b77]*/
+/*[clinic end generated code: output=1676433b9f04fbc9 input=a9049054013a1b77]*/
diff --git a/Objects/clinic/memoryobject.c.h b/Objects/clinic/memoryobject.c.h
index 64fce10..75ac201 100644
--- a/Objects/clinic/memoryobject.c.h
+++ b/Objects/clinic/memoryobject.c.h
@@ -3,7 +3,7 @@
 [clinic start generated code]*/
 
 PyDoc_STRVAR(memoryview_hex__doc__,
-"hex($self, /, sep=None, bytes_per_sep=1)\n"
+"hex($self, /, sep=<unrepresentable>, bytes_per_sep=1)\n"
 "--\n"
 "\n"
 "Return the data in the buffer as a str of hexadecimal numbers.\n"
@@ -71,4 +71,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=5e44e2bcf01057b5 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=ee265a73f68b0077 input=a9049054013a1b77]*/
diff --git a/Objects/clinic/unicodeobject.c.h b/Objects/clinic/unicodeobject.c.h
index cb35087..c7d6edb 100644
--- a/Objects/clinic/unicodeobject.c.h
+++ b/Objects/clinic/unicodeobject.c.h
@@ -630,7 +630,7 @@
 unicode_lstrip(PyObject *self, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    PyObject *chars = NULL;
+    PyObject *chars = Py_None;
 
     if (!_PyArg_CheckPositional("lstrip", nargs, 0, 1)) {
         goto exit;
@@ -664,7 +664,7 @@
 unicode_rstrip(PyObject *self, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    PyObject *chars = NULL;
+    PyObject *chars = Py_None;
 
     if (!_PyArg_CheckPositional("rstrip", nargs, 0, 1)) {
         goto exit;
@@ -1045,7 +1045,7 @@
 }
 
 PyDoc_STRVAR(unicode_maketrans__doc__,
-"maketrans(x, y=None, z=None, /)\n"
+"maketrans(x, y=<unrepresentable>, z=<unrepresentable>, /)\n"
 "--\n"
 "\n"
 "Return a translation table usable for str.translate().\n"
@@ -1232,4 +1232,4 @@
 {
     return unicode_sizeof_impl(self);
 }
-/*[clinic end generated code: output=d9a6ee45ddd0ccfd input=a9049054013a1b77]*/
+/*[clinic end generated code: output=5e15747f78f18329 input=a9049054013a1b77]*/
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 5c0640d..2f24105 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -2993,14 +2993,14 @@
     default: object = NULL
     /
 
-Remove specified key and return the corresponding value.
+D.pop(k[,d]) -> v, remove specified key and return the corresponding value.
 
 If key is not found, default is returned if given, otherwise KeyError is raised
 [clinic start generated code]*/
 
 static PyObject *
 dict_pop_impl(PyDictObject *self, PyObject *key, PyObject *default_value)
-/*[clinic end generated code: output=3abb47b89f24c21c input=016f6a000e4e633b]*/
+/*[clinic end generated code: output=3abb47b89f24c21c input=eeebec7812190348]*/
 {
     return _PyDict_Pop((PyObject*)self, key, default_value);
 }
diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index 20b7f51..8c08866 100644
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -1042,7 +1042,7 @@
 /*[clinic input]
 float.__round__
 
-    ndigits as o_ndigits: object = NULL
+    ndigits as o_ndigits: object = None
     /
 
 Return the Integral closest to x, rounding half toward even.
@@ -1052,13 +1052,13 @@
 
 static PyObject *
 float___round___impl(PyObject *self, PyObject *o_ndigits)
-/*[clinic end generated code: output=374c36aaa0f13980 input=1ca2316b510293b8]*/
+/*[clinic end generated code: output=374c36aaa0f13980 input=fc0fe25924fbc9ed]*/
 {
     double x, rounded;
     Py_ssize_t ndigits;
 
     x = PyFloat_AsDouble(self);
-    if (o_ndigits == NULL || o_ndigits == Py_None) {
+    if (o_ndigits == Py_None) {
         /* single-argument round or with None ndigits:
          * round to nearest integer */
         rounded = round(x);
diff --git a/Objects/structseq.c b/Objects/structseq.c
index 320bf08..c158afc 100644
--- a/Objects/structseq.c
+++ b/Objects/structseq.c
@@ -107,12 +107,12 @@
 @classmethod
 structseq.__new__ as structseq_new
     sequence as arg: object
-    dict: object = NULL
+    dict: object(c_default="NULL") = {}
 [clinic start generated code]*/
 
 static PyObject *
 structseq_new_impl(PyTypeObject *type, PyObject *arg, PyObject *dict)
-/*[clinic end generated code: output=baa082e788b171da input=9b44810243907377]*/
+/*[clinic end generated code: output=baa082e788b171da input=90532511101aa3fb]*/
 {
     PyObject *ob;
     PyStructSequence *res = NULL;
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index d4b2c93..070f795 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -12522,7 +12522,7 @@
 static PyObject *
 do_argstrip(PyObject *self, int striptype, PyObject *sep)
 {
-    if (sep != NULL && sep != Py_None) {
+    if (sep != Py_None) {
         if (PyUnicode_Check(sep))
             return _PyUnicode_XStrip(self, striptype, sep);
         else {
@@ -12559,7 +12559,7 @@
 /*[clinic input]
 str.lstrip as unicode_lstrip
 
-    chars: object = NULL
+    chars: object = None
     /
 
 Return a copy of the string with leading whitespace removed.
@@ -12569,7 +12569,7 @@
 
 static PyObject *
 unicode_lstrip_impl(PyObject *self, PyObject *chars)
-/*[clinic end generated code: output=3b43683251f79ca7 input=9e56f3c45f5ff4c3]*/
+/*[clinic end generated code: output=3b43683251f79ca7 input=529f9f3834448671]*/
 {
     return do_argstrip(self, LEFTSTRIP, chars);
 }
@@ -12578,7 +12578,7 @@
 /*[clinic input]
 str.rstrip as unicode_rstrip
 
-    chars: object = NULL
+    chars: object = None
     /
 
 Return a copy of the string with trailing whitespace removed.
@@ -12588,7 +12588,7 @@
 
 static PyObject *
 unicode_rstrip_impl(PyObject *self, PyObject *chars)
-/*[clinic end generated code: output=4a59230017cc3b7a input=ac89d0219cb411ee]*/
+/*[clinic end generated code: output=4a59230017cc3b7a input=62566c627916557f]*/
 {
     return do_argstrip(self, RIGHTSTRIP, chars);
 }
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index d069f2f..a40eb42 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -2140,7 +2140,7 @@
 round as builtin_round
 
     number: object
-    ndigits: object = NULL
+    ndigits: object = None
 
 Round a number to a given precision in decimal digits.
 
@@ -2150,7 +2150,7 @@
 
 static PyObject *
 builtin_round_impl(PyObject *module, PyObject *number, PyObject *ndigits)
-/*[clinic end generated code: output=ff0d9dd176c02ede input=854bc3a217530c3d]*/
+/*[clinic end generated code: output=ff0d9dd176c02ede input=275678471d7aca15]*/
 {
     PyObject *round, *result;
 
@@ -2168,7 +2168,7 @@
         return NULL;
     }
 
-    if (ndigits == NULL || ndigits == Py_None)
+    if (ndigits == Py_None)
         result = _PyObject_CallNoArg(round);
     else
         result = _PyObject_CallOneArg(round, ndigits);
diff --git a/Python/clinic/bltinmodule.c.h b/Python/clinic/bltinmodule.c.h
index 49608cc..b936b0c 100644
--- a/Python/clinic/bltinmodule.c.h
+++ b/Python/clinic/bltinmodule.c.h
@@ -719,7 +719,7 @@
     PyObject *argsbuf[2];
     Py_ssize_t noptargs = nargs + (kwnames ? PyTuple_GET_SIZE(kwnames) : 0) - 1;
     PyObject *number;
-    PyObject *ndigits = NULL;
+    PyObject *ndigits = Py_None;
 
     args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 2, 0, argsbuf);
     if (!args) {
@@ -849,4 +849,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=1927f3c9abd00c35 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=4e118c2cd2cd98f3 input=a9049054013a1b77]*/
diff --git a/Python/clinic/context.c.h b/Python/clinic/context.c.h
index eedfc88..2ac8bf7 100644
--- a/Python/clinic/context.c.h
+++ b/Python/clinic/context.c.h
@@ -115,7 +115,7 @@
 }
 
 PyDoc_STRVAR(_contextvars_ContextVar_get__doc__,
-"get($self, default=None, /)\n"
+"get($self, default=<unrepresentable>, /)\n"
 "--\n"
 "\n"
 "Return a value for the context variable for the current context.\n"
@@ -177,4 +177,4 @@
 
 #define _CONTEXTVARS_CONTEXTVAR_RESET_METHODDEF    \
     {"reset", (PyCFunction)_contextvars_ContextVar_reset, METH_O, _contextvars_ContextVar_reset__doc__},
-/*[clinic end generated code: output=a86b66e1516c25d4 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=f2e42f34e358e179 input=a9049054013a1b77]*/
diff --git a/Python/clinic/import.c.h b/Python/clinic/import.c.h
index 743d002..e4867f3 100644
--- a/Python/clinic/import.c.h
+++ b/Python/clinic/import.c.h
@@ -300,7 +300,7 @@
 #if defined(HAVE_DYNAMIC_LOADING)
 
 PyDoc_STRVAR(_imp_create_dynamic__doc__,
-"create_dynamic($module, spec, file=None, /)\n"
+"create_dynamic($module, spec, file=<unrepresentable>, /)\n"
 "--\n"
 "\n"
 "Create an extension module.");
@@ -454,4 +454,4 @@
 #ifndef _IMP_EXEC_DYNAMIC_METHODDEF
     #define _IMP_EXEC_DYNAMIC_METHODDEF
 #endif /* !defined(_IMP_EXEC_DYNAMIC_METHODDEF) */
-/*[clinic end generated code: output=ff06f7cf4b73eb76 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=3dc495e9c64d944e input=a9049054013a1b77]*/
diff --git a/Python/clinic/sysmodule.c.h b/Python/clinic/sysmodule.c.h
index f9ab28d..daca0e6 100644
--- a/Python/clinic/sysmodule.c.h
+++ b/Python/clinic/sysmodule.c.h
@@ -135,7 +135,7 @@
 sys_exit(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    PyObject *status = NULL;
+    PyObject *status = Py_None;
 
     if (!_PyArg_CheckPositional("exit", nargs, 0, 1)) {
         goto exit;
@@ -995,4 +995,4 @@
 #ifndef SYS_GETANDROIDAPILEVEL_METHODDEF
     #define SYS_GETANDROIDAPILEVEL_METHODDEF
 #endif /* !defined(SYS_GETANDROIDAPILEVEL_METHODDEF) */
-/*[clinic end generated code: output=8b250245a1265eef input=a9049054013a1b77]*/
+/*[clinic end generated code: output=decd687b7631de4b input=a9049054013a1b77]*/
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 476e154..9cc7b4b 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -749,7 +749,7 @@
 /*[clinic input]
 sys.exit
 
-    status: object = NULL
+    status: object = None
     /
 
 Exit the interpreter by raising SystemExit(status).
@@ -762,7 +762,7 @@
 
 static PyObject *
 sys_exit_impl(PyObject *module, PyObject *status)
-/*[clinic end generated code: output=13870986c1ab2ec0 input=a737351f86685e9c]*/
+/*[clinic end generated code: output=13870986c1ab2ec0 input=b86ca9497baa94f2]*/
 {
     /* Raise SystemExit so callers may catch it or clean up. */
     PyThreadState *tstate = _PyThreadState_GET();
diff --git a/Tools/clinic/clinic.py b/Tools/clinic/clinic.py
index cec7c53..c5edc7c 100755
--- a/Tools/clinic/clinic.py
+++ b/Tools/clinic/clinic.py
@@ -43,9 +43,6 @@
 
 version = '1'
 
-_empty = inspect._empty
-_void = inspect._void
-
 NoneType = type(None)
 
 class Unspecified:
@@ -2175,7 +2172,7 @@
     def __init__(self, parameters=None, *, name,
                  module, cls=None, c_basename=None,
                  full_name=None,
-                 return_converter, return_annotation=_empty,
+                 return_converter, return_annotation=inspect.Signature.empty,
                  docstring=None, kind=CALLABLE, coexist=False,
                  docstring_only=False):
         self.parameters = parameters or collections.OrderedDict()
@@ -2253,8 +2250,8 @@
     Mutable duck type of inspect.Parameter.
     """
 
-    def __init__(self, name, kind, *, default=_empty,
-                 function, converter, annotation=_empty,
+    def __init__(self, name, kind, *, default=inspect.Parameter.empty,
+                 function, converter, annotation=inspect.Parameter.empty,
                  docstring=None, group=0):
         self.name = name
         self.kind = kind
@@ -3231,6 +3228,8 @@
             # sorry, clinic can't support preallocated buffers
             # for es# and et#
             self.c_default = "NULL"
+        if NoneType in accept and self.c_default == "Py_None":
+            self.c_default = "NULL"
 
     def cleanup(self):
         if self.encoding:
@@ -4433,7 +4432,7 @@
                 # mild hack: explicitly support NULL as a default value
                 if isinstance(expr, ast.Name) and expr.id == 'NULL':
                     value = NULL
-                    py_default = 'None'
+                    py_default = '<unrepresentable>'
                     c_default = "NULL"
                 elif (isinstance(expr, ast.BinOp) or
                     (isinstance(expr, ast.UnaryOp) and