Issue #13575: there is only one class type.
diff --git a/Lib/pickle.py b/Lib/pickle.py
index a911ca0..ca36274 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -375,7 +375,7 @@
             # allowing protocol 0 and 1 to work normally.  For this to
             # work, the function returned by __reduce__ should be
             # called __newobj__, and its first argument should be a
-            # new-style class.  The implementation for __newobj__
+            # class.  The implementation for __newobj__
             # should be as follows, although pickle has no way to
             # verify this:
             #
diff --git a/Lib/pickletools.py b/Lib/pickletools.py
index 515d375..9086416 100644
--- a/Lib/pickletools.py
+++ b/Lib/pickletools.py
@@ -1639,6 +1639,8 @@
       is pushed on the stack.
 
       NOTE:  checks for __safe_for_unpickling__ went away in Python 2.3.
+      NOTE:  the distinction between old-style and new-style classes does
+             not make sense in Python 3.
       """),
 
     I(name='OBJ',