I'm hoping to make a pull request but while I figure that out here is the diff:

diff --git a/Lib/collections/__init__.py b/Lib/collections/__init__.py
index 8408255..62cf708 100644
--- a/Lib/collections/__init__.py
+++ b/Lib/collections/__init__.py
@@ -384,7 +384,6 @@ def namedtuple(typename, field_names, *, verbose=False, rename=False, module=Non
     if isinstance(field_names, str):
         field_names = field_names.replace(',', ' ').split()
     field_names = list(map(str, field_names))
-    typename = str(typename)
     if rename:
         seen = set()
         for index, name in enumerate(field_names):
@@ -394,6 +393,10 @@ def namedtuple(typename, field_names, *, verbose=False, rename=False, module=Non
                 or name in seen):
                 field_names[index] = '_%d' % index
             seen.add(name)
+    if typename is None:
+        typename = '__'.join (field_names)
+    else:
+        typename = str(typename)
     for name in [typename] + field_names:
         if type(name) is not str:
             raise TypeError('Type names and field names must be strings')