diff --git a/Doc/library/xml.etree.elementtree.rst b/Doc/library/xml.etree.elementtree.rst
--- a/Doc/library/xml.etree.elementtree.rst
+++ b/Doc/library/xml.etree.elementtree.rst
@@ -32,17 +32,21 @@
 The :class:`ElementTree` class can be used to wrap an element structure, and
 convert it from and to XML.
 
-A C implementation of this API is available as :mod:`xml.etree.cElementTree`.
+This module has a transparent optimizer (:mod:`_elementtree`) written in C.
+It is used whenever available.  Otherwise the pure Python implementation is
+used.
 
 See http://effbot.org/zone/element-index.htm for tutorials and links to other
-docs.  Fredrik Lundh's page is also the location of the development version of
-the xml.etree.ElementTree.
+docs.
 
 .. versionchanged:: 3.2
    The ElementTree API is updated to 1.3.  For more information, see
    `Introducing ElementTree 1.3
    <http://effbot.org/zone/elementtree-13-intro.htm>`_.
 
+.. versionchanged:: 3.3
+   The C optimizer (:mod:`_elementtree`) is now used by default whenever
+   available.  :mod:`cElementTree` is deprecated.
 
 .. _elementtree-functions:
 
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -1872,6 +1872,10 @@
 - Issue #12191: Added shutil.chown() to change user and/or group owner of a
   given path also specifying their names.
 
+- Issue #13988: The _elementtree optimizer is now used by default (whenever
+  available) when xml.etree.ElementTree is imported. cElementTree is now
+  deprecated.
+
 Build
 -----