diff --git a/firestar/builder.nix b/firestar/builder.nix
index 9586e16..81d3200 100644
--- a/firestar/builder.nix
+++ b/firestar/builder.nix
@@ -11,7 +11,8 @@
     };
   };
 
-  nix.extraOptions = ''
-  trusted-users = root builder
-  '';
+  nix.settings.trusted-users = [
+    "root"
+    "builder"
+  ];
 }