diff --git a/shell.nix b/shell.nix
index 9b9e252..7f48806 100644
--- a/shell.nix
+++ b/shell.nix
@@ -48,5 +48,5 @@ pkgs.mkShell {
     (sources.disko + "/package.nix")
   ])) ++ (import ./scripts { inherit pkgs; });
 
-  allowSubstitutes = false;
+  preferLocalBuild = true;
 }