diff --git a/Doc/library/htmlparser.rst b/Doc/library/htmlparser.rst
index aa10498042b..adbcb38d9cd 100644
--- a/Doc/library/htmlparser.rst
+++ b/Doc/library/htmlparser.rst
@@ -64,7 +64,8 @@ An exception is defined as well:
Feed some text to the parser. It is processed insofar as it consists of
complete elements; incomplete data is buffered until more data is fed or
- :meth:`close` is called.
+ :meth:`close` is called. *data* can be either :class:`unicode` or
+ :class:`str`, but passing :class:`unicode` is advised.
.. method:: HTMLParser.close()