diff --git a/pkgs/development/python-modules/mkdocs-rss-plugin/default.nix b/pkgs/development/python-modules/mkdocs-rss-plugin/default.nix
index d21f09234b2e..a49427e0b1a3 100644
--- a/pkgs/development/python-modules/mkdocs-rss-plugin/default.nix
+++ b/pkgs/development/python-modules/mkdocs-rss-plugin/default.nix
@@ -34,7 +34,7 @@ buildPythonPackage rec {
     cachecontrol
     gitpython
     mkdocs
-  ];
+  ] ++ cachecontrol.optional-dependencies.filecache;
 
   nativeCheckInputs = [
     feedparser