Replace mentions of IOError
diff --git a/Doc/library/gettext.rst b/Doc/library/gettext.rst
index 0fa022c..825311b 100644
--- a/Doc/library/gettext.rst
+++ b/Doc/library/gettext.rst
@@ -185,10 +185,13 @@
    translation object from the cache; the actual instance data is still shared with
    the cache.
 
-   If no :file:`.mo` file is found, this function raises :exc:`IOError` if
+   If no :file:`.mo` file is found, this function raises :exc:`OSError` if
    *fallback* is false (which is the default), and returns a
    :class:`NullTranslations` instance if *fallback* is true.
 
+   .. versionchanged:: 3.3
+      :exc:`IOError` used to be raised instead of :exc:`OSError`.
+
 
 .. function:: install(domain, localedir=None, codeset=None, names=None)
 
@@ -342,7 +345,7 @@
 
 If the :file:`.mo` file's magic number is invalid, or if other problems occur
 while reading the file, instantiating a :class:`GNUTranslations` class can raise
-:exc:`IOError`.
+:exc:`OSError`.
 
 The following methods are overridden from the base class implementation: