diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index 8aba6b3..6a46549 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -802,7 +802,7 @@
 
 static int obj2ast_identifier(PyObject* obj, PyObject** out, PyArena* arena)
 {
-    if (!PyString_CheckExact(obj)) {
+    if (!PyString_CheckExact(obj) && obj != Py_None) {
         PyErr_Format(PyExc_TypeError,
                     "AST identifier must be of type str");
         return 1;