diff --git a/Lib/xml/etree/ElementTree.py b/Lib/xml/etree/ElementTree.py
index 168418e..9924680 100644
--- a/Lib/xml/etree/ElementTree.py
+++ b/Lib/xml/etree/ElementTree.py
@@ -252,7 +252,7 @@ def extend(self, elements):
         """
         for element in elements:
             self._assert_is_element(element)
-        self._children.extend(elements)
+            self._children.append(element)
 
     def insert(self, index, subelement):
         """Insert *subelement* at position *index*."""