Replace mentions of IOError
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 4ed3ec5..22e2468 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -783,7 +783,7 @@
.. function:: open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True)
Open *file* and return a corresponding stream. If the file cannot be opened,
- an :exc:`IOError` is raised.
+ an :exc:`OSError` is raised.
*file* is either a string or bytes object giving the pathname (absolute or
relative to the current working directory) of the file to be opened or
@@ -912,6 +912,9 @@
(where :func:`open` is declared), :mod:`os`, :mod:`os.path`, :mod:`tempfile`,
and :mod:`shutil`.
+ .. versionchanged:: 3.3
+ :exc:`IOError` used to be raised, it is now an alias of :exc:`OSError`.
+
.. XXX works for bytes too, but should it?
.. function:: ord(c)