Do not assume that types.UnicodeType exists; we might be running in an old
version of Python.  ;-(
diff --git a/Lib/xml/sax/saxutils.py b/Lib/xml/sax/saxutils.py
index 83c779f..e592f2a 100644
--- a/Lib/xml/sax/saxutils.py
+++ b/Lib/xml/sax/saxutils.py
@@ -7,7 +7,11 @@
 import handler
 import xmlreader
 
-_StringTypes = [types.StringType, types.UnicodeType]
+try:
+    _StringTypes = [types.StringType, types.UnicodeType]
+except AttributeError:
+    _StringTypes = [types.StringType]
+
 
 def escape(data, entities={}):
     """Escape &, <, and > in a string of data.