diff --git a/docs/topics/downloader-middleware.rst b/docs/topics/downloader-middleware.rst
index 80c6c2c37..99d57bda9 100644
--- a/docs/topics/downloader-middleware.rst
+++ b/docs/topics/downloader-middleware.rst
@@ -1070,9 +1070,13 @@ In order to use this parser:
 
 * Install `Reppy <https://github.com/seomoz/reppy/>`_ by running ``pip install reppy``
 
+    .. warning:: `Upstream issue #122
+        <https://github.com/seomoz/reppy/issues/122>`_ prevents reppy usage in Python 3.9+.
+
 * Set :setting:`ROBOTSTXT_PARSER` setting to
   ``scrapy.robotstxt.ReppyRobotParser``
 
+
 .. _rerp-parser:
 
 Robotexclusionrulesparser