Mar 9, 2026
diff --git a/Lib/test/test_ast/test_ast.py b/Lib/test/test_ast/test_ast.py
            ("None",b"N\xc2\xbane"),
        ]
 forconstantinconstants:
 withself.assertRaisesRegex(ValueError,
 withself.assertRaisesRegex(SyntaxError,
 f"identifier field can't represent '{constant[0]}' constant"):
 ast.parse(constant[1],mode="eval")

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-03-09-17-19-04.gh-issue-145675.9YPpYi.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-09-17-19-04.gh-issue-145675.9YPpYi.rst
 Raise :exc:`SyntaxError` when constants ``True``, ``False`` or ``None`` are
 used as an identifier after NFKC normalization.
diff --git a/Parser/pegen.c b/Parser/pegen.c
    };
 for (inti=0;forbidden[i]!=NULL;i++) {
 if (_PyUnicode_EqualToASCIIString(id,forbidden[i])) {
 PyErr_Format(PyExc_ValueError,
 RAISE_SYNTAX_ERROR(
 "identifier field can't represent '%s' constant",
 forbidden[i]);
 Py_DECREF(id);
Original file line number	Diff line number	Diff line change
Expand Up		@@ -954,7 +954,7 @@ def test_constant_as_unicode_name(self):
		("None",b"N\xc2\xbane"),
		]
		forconstantinconstants:
		withself.assertRaisesRegex(ValueError,
		withself.assertRaisesRegex(SyntaxError,
		f"identifier field can't represent '{constant[0]}' constant"):
		ast.parse(constant[1],mode="eval")

Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Raise :exc:`SyntaxError` when constants ``True``, ``False`` or ``None`` are
		used as an identifier after NFKC normalization.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -539,7 +539,7 @@ _PyPegen_new_identifier(Parser p, const char n)
		};
		for (inti=0;forbidden[i]!=NULL;i++) {
		if (_PyUnicode_EqualToASCIIString(id,forbidden[i])) {
		PyErr_Format(PyExc_ValueError,
		RAISE_SYNTAX_ERROR(
		"identifier field can't represent '%s' constant",
		forbidden[i]);
		Py_DECREF(id);
Expand Down