diff -r fd9f7bdd7472 Lib/test/test_xml_etree.py
--- a/Lib/test/test_xml_etree.py	Fri Jun 20 01:38:37 2014 -0700
+++ b/Lib/test/test_xml_etree.py	Sun Jun 22 14:02:28 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 fd9f7bdd7472 Lib/xml/etree/ElementInclude.py
--- a/Lib/xml/etree/ElementInclude.py	Fri Jun 20 01:38:37 2014 -0700
+++ b/Lib/xml/etree/ElementInclude.py	Sun Jun 22 14:02:28 2014 -0400
@@ -114,6 +114,7 @@
                         "cannot load %r as %r" % (href, parse)
                         )
                 node = copy.copy(node)
+                _include(node,loader,[href])
                 if e.tail:
                     node.tail = (node.tail or "") + e.tail
                 elem[i] = node
@@ -141,3 +142,73 @@
         else:
             include(e, loader)
         i = i + 1
+
+##
+# 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):
+        e = elem[i]
+        if e.tag == XINCLUDE_INCLUDE:
+            # process xinclude directive
+            href = e.get("href")
+            parse = e.get("parse", "xml")
+            if parse == "xml":
+                node = loader(href, parse)
+                if node is None:
+                    raise FatalIncludeError(
+                        "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) ### newly added code here
+                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
+            elif parse == "text":
+                text = loader(href, parse, e.get("encoding"))
+                if text is None:
+                    raise FatalIncludeError(
+                        "cannot load %r as %r" % (href, parse)
+                        )
+                if i:
+                    node = elem[i-1]
+                    node.tail = (node.tail or "") + text + (e.tail or "")
+                else:
+                    elem.text = (elem.text or "") + text + (e.tail or "")
+                del elem[i]
+                continue
+            else:
+                raise FatalIncludeError(
+                    "unknown parse type in xi:include tag (%r)" % parse
+                )
+        elif e.tag == XINCLUDE_FALLBACK:
+            raise FatalIncludeError(
+                "xi:fallback tag must be child of xi:include (%r)" % e.tag
+                )
+        else:
+            include(e, loader)
+        i = i + 1