diff --git a/nix/configuration/configuration.nix b/nix/configuration/configuration.nix
index a443861..d1375bd 100644
--- a/nix/configuration/configuration.nix
+++ b/nix/configuration/configuration.nix
@@ -108,10 +108,8 @@
     hardware.enableRedistributableFirmware = true;
 
     # Keep outputs so we can build offline.
-    nix.extraOptions = ''
-      keep-outputs = true
-      keep-derivations = true
-    '';
+    nix.settings.keep-outputs = true;
+    nix.settings.keep-derivations = true;
 
     # Automatic garbage collection
     nix.gc = lib.mkIf (!config.me.buildingPortable) {
diff --git a/nix/configuration/roles/dont_use_substituters/default.nix b/nix/configuration/roles/dont_use_substituters/default.nix
index 5672b66..0982ff2 100644
--- a/nix/configuration/roles/dont_use_substituters/default.nix
+++ b/nix/configuration/roles/dont_use_substituters/default.nix
@@ -19,10 +19,7 @@
 
   config = lib.mkIf config.me.dont_use_substituters.enable {
     # Disable substituters to avoid risk of cache poisoning.
-    nix.extraOptions = ''
-      substitute = false
-    '';
-
+    nix.settings.substitute = false;
     nix.settings.substituters = lib.mkForce [ ];
   };
 }