diff --git a/hosts/ornithologist/default.nix b/hosts/ornithologist/default.nix
index ae36071..9b00f9a 100644
--- a/hosts/ornithologist/default.nix
+++ b/hosts/ornithologist/default.nix
@@ -7,4 +7,31 @@
 
   # Enable docker.
   flock.docker.enable = true;
+
+  # Deploy NixOS updates once a week.
+  systemd.timers."deploy-rs" = {
+    wantedBy = ["timers.target"];
+    timerConfig = {
+      OnCalendar = "weekly";
+      Persistent = true;
+      Unit = "deploy-rs.service";
+    };
+  };
+
+  systemd.services."deploy-rs" = {
+    path = with pkgs; [openssh git nix deploy-rs];
+    script = ''
+      set -eu
+
+      cd /home/fern/Repositories/flock
+      git pull && nix flake update
+
+      deploy && git commit -m "[ornithologist] Update flake.lock" && git push
+    '';
+    serviceConfig = {
+      Type = "oneshot";
+      User = "fern";
+      Group = "users";
+    };
+  };
 }