diff --git a/.gitea/workflows/ci.yaml b/.gitea/workflows/ci.yaml
index da774b9..3dd8537 100644
--- a/.gitea/workflows/ci.yaml
+++ b/.gitea/workflows/ci.yaml
@@ -20,6 +20,7 @@ jobs:
           extra_nix_config: |
             # Make sure we're using sandbox
             sandbox-fallback = false
+
             extra-substituters = https://nix-cache.nul.ie/main
             extra-trusted-public-keys = main:mMChkG8LwXrFirVfudqjSHasK1jV31OVElYD3eImYl8=
       - name: Set up attic
diff --git a/devshell/default.nix b/devshell/default.nix
index fce4efd..66ba449 100644
--- a/devshell/default.nix
+++ b/devshell/default.nix
@@ -1,6 +1,5 @@
 { lib, pkgs, ... }:
 let
-  inherit (lib) concatStringsSep;
   inherit (lib.my) attrsToNVList;
 in
 {
@@ -13,9 +12,7 @@ in
     NIX_USER_CONF_FILES = toString (pkgs.writeText "nix.conf"
       ''
         experimental-features = nix-command flakes ca-derivations repl-flake
-        #substituters = https://nix-cache.nul.ie https://cache.nixos.org
-        substituters = https://cache.nixos.org
-        trusted-public-keys = ${concatStringsSep " " lib.my.c.nix.cacheKeys}
+        ${lib.my.c.nix.cache.conf}
       '');
 
     INSTALLER_SSH_OPTS = "-i .keys/deploy.key";
diff --git a/home-manager/modules/common.nix b/home-manager/modules/common.nix
index d2a7ac0..049d01e 100644
--- a/home-manager/modules/common.nix
+++ b/home-manager/modules/common.nix
@@ -235,12 +235,9 @@ in
             exact = true;
           };
         };
-        settings = {
-          substituters = [
-            #"https://nix-cache.nul.ie"
-            "https://cache.nixos.org"
-          ];
-          trusted-public-keys = lib.my.c.nix.cacheKeys;
+        settings = with lib.my.c.nix; {
+          extra-substituters = cache.substituters;
+          extra-trusted-public-keys = cache.keys;
         };
       };
     })
diff --git a/lib/constants.nix b/lib/constants.nix
index 24e7751..ed8f4f2 100644
--- a/lib/constants.nix
+++ b/lib/constants.nix
@@ -1,4 +1,8 @@
-{ lib }: rec {
+{ lib }:
+let
+  inherit (lib) concatStringsSep;
+in
+rec {
   # See https://github.com/NixOS/nixpkgs/blob/master/nixos/modules/misc/ids.nix
   ids = {
     uids = {
@@ -32,10 +36,18 @@
   };
 
   nix = {
-    cacheKeys = [
-      "nix-cache.nul.ie-1:XofkqdHQSGFoPjB6aRohQbCU2ILKFqhNjWfoOdQgF5Y="
-      "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
-    ];
+    cache = rec {
+      substituters = [
+        "https://nix-cache.${pubDomain}/main"
+      ];
+      keys = [
+        "main:mMChkG8LwXrFirVfudqjSHasK1jV31OVElYD3eImYl8="
+      ];
+      conf = ''
+        extra-substituters = ${concatStringsSep " " substituters}
+        extra-trusted-public-keys = ${concatStringsSep " " keys}
+      '';
+    };
   };
 
   pubDomain = "nul.ie";
diff --git a/nixos/modules/common.nix b/nixos/modules/common.nix
index c7383a7..e5230d7 100644
--- a/nixos/modules/common.nix
+++ b/nixos/modules/common.nix
@@ -41,14 +41,11 @@ in
 
       nix = {
         package = pkgs'.mine.nix;
-        settings = {
+        settings = with lib.my.c.nix; {
           trusted-users = [ "@wheel" ];
           experimental-features = [ "nix-command" "flakes" "ca-derivations" ];
-          substituters = [
-            #"https://nix-cache.nul.ie"
-            "https://cache.nixos.org"
-          ];
-          trusted-public-keys = lib.my.c.nix.cacheKeys;
+          extra-substituters = cache.substituters;
+          extra-trusted-public-keys = cache.keys;
         };
         registry = {
           pkgs = {