diff --git a/modules/services/dmz/hydra.nix b/modules/services/dmz/hydra.nix
index 1fa2d9d..fa14160 100644
--- a/modules/services/dmz/hydra.nix
+++ b/modules/services/dmz/hydra.nix
@@ -20,7 +20,7 @@
       ];
 
       extraOptions = ''
-        secret-key-files = $(cat "${config.age.secrets."keys/nixsign".path}");
+        secret-key-files = ${config.age.secrets."keys/nixsign".path};
       '';
     };