diff --git a/packages.nix b/packages.nix
index ba14544f..a97eb502 100644
--- a/packages.nix
+++ b/packages.nix
@@ -100,7 +100,7 @@ lib.attrsets.mapAttrs
       let
         host = getHostAddr name;
         target = ''root@"${host}"'';
-        rebuildArg = "--flake ${self}#${name} --option extra-substituters https://nix-serve.hq.c3d2.de --accept-flake-config";
+        rebuildArg = "--flake ${self}#${name} ${overrideInputsArgs} --accept-flake-config";
         hostConfig = self.nixosConfigurations."${name}".config;
         # let /var/lib/microvm/*/flake point to the flake-update branch so that
         # `microvm -u $NAME` updates to what hydra built today.