diff --git a/machine/not522/installer/default.nix b/machine/not522/installer/default.nix
index b61493f8..ebae55e6 100644
--- a/machine/not522/installer/default.nix
+++ b/machine/not522/installer/default.nix
@@ -39,4 +39,9 @@ in {
       exec ${pkgs.disko}/bin/disko-install --flake "${nixos-config}#not522" --disk main "${nixos-config.nixosConfigurations.not522.config.disko.devices.disk.main.device}"
     '')
   ];
+  nix.settings.substituters = lib.mkForce [
+    "https://attic.chir.rs/chir-rs/"
+    "https://hydra.chir.rs"
+    "https://cache.nixos.org"
+  ];
 }
diff --git a/machine/pc-installer/default.nix b/machine/pc-installer/default.nix
index 91af8dfb..fefa518b 100644
--- a/machine/pc-installer/default.nix
+++ b/machine/pc-installer/default.nix
@@ -1,6 +1,7 @@
 {
   config,
   nixos-config,
+  lib,
   ...
 }: {
   networking.hostName = "pc-installer";
@@ -17,4 +18,9 @@
       ./graphical.nix
     ];
   };
+  nix.settings.substituters = lib.mkForce [
+    "https://attic.chir.rs/chir-rs/"
+    "https://hydra.chir.rs"
+    "https://cache.nixos.org"
+  ];
 }