Index: _elementtree.c
===================================================================
--- _elementtree.c	(revision 73491)
+++ _elementtree.c	(working copy)
@@ -1697,6 +1697,16 @@
     return (PyObject*) self->last;
 }
 
+const char *
+str_encoding(const char *st)
+{
+    PyObject* dec;
+
+    dec = PyUnicode_DecodeUTF8(st, strlen(st), "strict");
+    dec = PyUnicode_AsLatin1String(dec);
+    return PyString_AsString(dec);
+}
+
 LOCAL(void)
 treebuilder_handle_namespace(TreeBuilderObject* self, int start,
                              const char* prefix, const char *uri)
@@ -1712,8 +1722,15 @@
         if (!self->start_ns_event_obj)
             return;
         action = self->start_ns_event_obj;
-        /* FIXME: prefix and uri use utf-8 encoding! */
-        parcel = Py_BuildValue("ss", (prefix) ? prefix : "", uri);
+
+	/* These are utf-8 encoded. str_encoding is an ugly hack
+	   so that cElementTree outputs the same as ElementTree 
+	   Issue 6266
+	*/
+	parcel = Py_BuildValue("ss",
+			       (prefix) ? str_encoding(prefix) : "",
+			       str_encoding(uri));
+
         if (!parcel)
             return;
         Py_INCREF(action);