diff -r cb04c94014ea Lib/test/test_xml_etree.py
--- a/Lib/test/test_xml_etree.py	Thu Jun 26 01:36:47 2014 +0200
+++ b/Lib/test/test_xml_etree.py	Thu Jun 26 01:09:24 2014 -0400
@@ -1185,6 +1185,30 @@
 </document>
 """.format(html.escape(SIMPLE_XMLFILE, True))
 
+XINCLUDE["Recursive1.xml"] = """\
+<?xml version='1.0'?>
+<document xmlns:xi="http://www.w3.org/2001/XInclude">
+  <p>The following is the source code of Recursive2.xml:</p>
+  <xi:include href="Recursive2.xml"/>
+</document>
+"""
+
+XINCLUDE["Recursive2.xml"] = """\
+<?xml version='1.0'?>
+<document xmlns:xi="http://www.w3.org/2001/XInclude">
+  <p>The following is the source code of Recursive2.xml:</p>
+  <xi:include href="Recursive3.xml"/>
+</document>
+"""
+
+XINCLUDE["Recursive3.xml"] = """\
+<?xml version='1.0'?>
+<document xmlns:xi="http://www.w3.org/2001/XInclude">
+  <p>The following is the source code of Recursive2.xml:</p>
+  <xi:include href="Recursive1.xml"/>
+</document>
+"""
+
 #
 # badly formatted xi:include tags
 
@@ -1306,6 +1330,12 @@
             '  </ns0:include>\n'
             '</div>') # C5
 
+        document = self.xinclude_loader("Recursive1.xml")
+        with self.assertRaises(SyntaxError) as cm:
+            ElementInclude.include(document,self.xinclude_loader)
+        self.assertEqual(str(cm.exception),"recursive include detected: loaded Recursive2.xml more than once")
+
+
     def test_xinclude_failures(self):
         from xml.etree import ElementInclude
 
diff -r cb04c94014ea Lib/xml/etree/ElementInclude.py
--- a/Lib/xml/etree/ElementInclude.py	Thu Jun 26 01:36:47 2014 +0200
+++ b/Lib/xml/etree/ElementInclude.py	Thu Jun 26 01:09:24 2014 -0400
@@ -97,8 +97,28 @@
 # @throws OSError If the function fails to load a given resource.
 
 def include(elem, loader=None):
+    _include(elem, loader, None)
+
+##
+# Expand XInclude directives. Helper function identical to include, 
+# Only difference is that the already_included array detects
+# recursive includes. 
+#
+# @param elem Root element.
+# @param loader Optional resource loader.  If omitted, it defaults
+#     to {@link default_loader}.  If given, it should be a callable
+#     that implements the same interface as <b>default_loader</b>.
+# @param already_included includes a list of already included files
+#     in order (prevention of infinite include condition)
+# @throws FatalIncludeError If the function fails to include a given
+#     resource, or if the tree contains malformed XInclude elements.
+# @throws OSError If the function fails to load a given resource.
+
+def _include(elem, loader=None, already_included=None):
     if loader is None:
         loader = default_loader
+    if already_included == None:
+        already_included = []
     # look for xinclude elements
     i = 0
     while i < len(elem):
@@ -114,6 +134,13 @@
                         "cannot load %r as %r" % (href, parse)
                         )
                 node = copy.copy(node)
+                if not href in already_included:
+                    already_included.append(href)
+                    _include(node,loader,already_included) 
+                else:
+                    raise FatalIncludeError(
+                            "recursive include detected: loaded %s more than once" % (href)    
+                        )
                 if e.tail:
                     node.tail = (node.tail or "") + e.tail
                 elem[i] = node