diff --git a/jinja2/runtime.py b/jinja2/runtime.py
index ae394e3..be5b09a 100644
--- a/jinja2/runtime.py
+++ b/jinja2/runtime.py
@@ -454,6 +454,10 @@
     def __str__(self):
         return unicode(self).encode('utf-8')
 
+    # unicode goes after __str__ because we configured 2to3 to rename
+    # __unicode__ to __str__.  because the 2to3 tree is not designed to
+    # remove nodes from it, we leave the above __str__ around and let
+    # it override at runtime.
     def __unicode__(self):
         return u''