diff --git a/nixos/modules/services/web-apps/filesender.md b/nixos/modules/services/web-apps/filesender.md
index 44d066761b9a..bb971fb984e5 100644
--- a/nixos/modules/services/web-apps/filesender.md
+++ b/nixos/modules/services/web-apps/filesender.md
@@ -9,6 +9,9 @@ FileSender uses [SimpleSAMLphp](https://simplesamlphp.org/) for authentication,
 Minimal working instance of FileSender that uses password-authentication would look like this:
 
 ```nix
+let
+  format = pkgs.formats.php {};
+in
 {
   networking.firewall.allowedTCPPorts = [ 80 443 ];
   services.filesender = {