diff --git a/common.nix b/common.nix
index c3ed937..e9b4369 100644
--- a/common.nix
+++ b/common.nix
@@ -5,18 +5,23 @@
 
   console = {
     keyMap = "us";
-    font = "Lat2-Terminus16";
+    font   = "Lat2-Terminus16";
   };
 
   i18n.defaultLocale = "en_US.UTF-8";
 
   nix = {
     autoOptimiseStore = true;
-    nixPath = [
+    nixPath           = [
       "nixpkgs=/nix/var/nix/profiles/per-user/root/channels/nixos"
       "nixos-config=/etc/nixos/hosts/${variables.hostname}/default.nix"
       "/nix/var/nix/profiles/per-user/root/channels"
     ];
+    gc = {
+      automatic  = true;
+      dates      = "weekly";
+      persistent = true;
+    };
   };
 
   nixpkgs = {