List what classes from importlib.machinery don't work with importlib.util.LazyLoader
diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst
index 23432e1..43b34e9 100644
--- a/Doc/library/importlib.rst
+++ b/Doc/library/importlib.rst
@@ -1273,7 +1273,8 @@
    :meth:`~importlib.abc.Loader.exec_module` as control over what module type
    is used for the module is required. For those same reasons, the loader's
    :meth:`~importlib.abc.Loader.create_module` method will be ignored (i.e., the
-   loader's method should only return ``None``). Finally,
+   loader's method should only return ``None``; this excludes
+   :class:`BuiltinImporter` and :class:`ExtensionFileLoader`). Finally,
    modules which substitute the object placed into :attr:`sys.modules` will
    not work as there is no way to properly replace the module references
    throughout the interpreter safely; :exc:`ValueError` is raised if such a