diff --git a/docs/topics/downloader-middleware.rst b/docs/topics/downloader-middleware.rst
index ca597291f..33308940c 100644
--- a/docs/topics/downloader-middleware.rst
+++ b/docs/topics/downloader-middleware.rst
@@ -1251,6 +1251,10 @@ Default: ``False``
 
 Whether the AjaxCrawlMiddleware will be enabled.
 
+   .. note::
+
+       This middleware is deprecated and will be removed in a future Scrapy release.
+
 HttpProxyMiddleware settings
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~