diff --git a/hosts/hydra/default.nix b/hosts/hydra/default.nix
index 43fea15a..08dbf8ca 100644
--- a/hosts/hydra/default.nix
+++ b/hosts/hydra/default.nix
@@ -221,6 +221,7 @@
       };
       "ssh-keys/hydra/private" = {
         owner = "hydra";
+        # used for cloning flake inputs
         path = "/var/lib/hydra/.ssh/id_ed25519";
       };
       "ssh-keys/hydra/public" = {
@@ -230,6 +231,7 @@
       };
       "ssh-keys/root/private" = {
         owner = "hydra-queue-runner";
+        # used to build the actual derivations
         path = "/var/lib/hydra/queue-runner/.ssh/id_ed25519";
       };
       "ssh-keys/root/public" = {