diff --git a/hosts/docker/default.nix b/hosts/docker/default.nix
index fd5b3d4..399dcf5 100644
--- a/hosts/docker/default.nix
+++ b/hosts/docker/default.nix
@@ -35,6 +35,7 @@
 
   users.users.fern.extraGroups = ["media"];
 
+  # Enable docker.
   flock.docker = {
     enable = true;
     dockerMount = true;
diff --git a/hosts/minecraft/default.nix b/hosts/minecraft/default.nix
index 965fea0..d35f05c 100644
--- a/hosts/minecraft/default.nix
+++ b/hosts/minecraft/default.nix
@@ -1,4 +1,5 @@
 {
+  # Enable docker.
   flock.docker = {
     enable = true;
     dockerMount = true;
diff --git a/hosts/musicbrainz/default.nix b/hosts/musicbrainz/default.nix
index a78b952..334845e 100644
--- a/hosts/musicbrainz/default.nix
+++ b/hosts/musicbrainz/default.nix
@@ -21,6 +21,7 @@
     };
   };
 
+  # Enable docker.
   flock.docker = {
     enable = true;
     dockerMount = true;
diff --git a/hosts/muskduck/default.nix b/hosts/muskduck/default.nix
index 9703476..553373b 100644
--- a/hosts/muskduck/default.nix
+++ b/hosts/muskduck/default.nix
@@ -1,4 +1,4 @@
-{lib, ...}:
+{pkgs, lib, ...}:
 with lib; {
   # Kernel modules.
   boot.initrd.availableKernelModules = ["xhci_pci" "nvme" "usb_storage" "sd_mod"];
@@ -47,4 +47,7 @@ with lib; {
   };
 
   swapDevices = [{device = "/swap/swapfile";}];
+
+  # Install some packages.
+  environment.systemPackages = with pkgs; [deploy-rs];
 }
diff --git a/hosts/weebill/default.nix b/hosts/weebill/default.nix
index d4dd740..b5bd903 100644
--- a/hosts/weebill/default.nix
+++ b/hosts/weebill/default.nix
@@ -120,6 +120,7 @@
     allowedTCPPorts = [8080 548 80 7125]; # WebOne, Netatalk, nginx, moonraker.
   };
 
+  # Enable docker.
   flock.docker = {
     enable = true;
   };