diff --git a/jinja2/lexer.py b/jinja2/lexer.py
index b974199..98d85d9 100644
--- a/jinja2/lexer.py
+++ b/jinja2/lexer.py
@@ -530,7 +530,8 @@
                     raise TemplateSyntaxError(msg, lineno, name, filename)
                 # if we can express it as bytestring (ascii only)
                 # we do that for support of semi broken APIs
-                # as datetime.datetime.strftime
+                # as datetime.datetime.strftime.  On python 3 this
+                # call becomes a noop thanks to 2to3
                 try:
                     value = str(value)
                 except UnicodeError: