diff --git a/nixng/containers/hydra/hydra.nix b/nixng/containers/hydra/hydra.nix
index af29d0c..40eeee1 100644
--- a/nixng/containers/hydra/hydra.nix
+++ b/nixng/containers/hydra/hydra.nix
@@ -57,7 +57,12 @@ makeSystem {
         minimumDiskFreeEvaluator = 100;
 
         dbiFile = "/local/dbi";
-        config.evaluator_max_memory_size = "2048M";
+        config = {
+          evaluator_max_memory_size = "2048M";
+          store_uri = "daemon?secret-key=/secrets/nix-key.private";
+          binary_cache_secret_key_file = "/secrets/nix-key.private";
+          server_store_uri = "daemon?secret-key=/secrets/nix-key.private";
+        };
       };
       services.socklog = {
         enable = true;