diff --git a/nixos/modules/misc/documentation.nix b/nixos/modules/misc/documentation.nix
index 9304c307af2..8e28d3336fa 100644
--- a/nixos/modules/misc/documentation.nix
+++ b/nixos/modules/misc/documentation.nix
@@ -64,7 +64,8 @@ let
         filter =
           builtins.filterSource
             (n: t:
-              (t == "directory" -> baseNameOf n != "tests")
+              cleanSourceFilter n t
+              && (t == "directory" -> baseNameOf n != "tests")
               && (t == "file" -> hasSuffix ".nix" n)
             );
       in