diff --git a/default.nix b/default.nix
index db891a0..9eda67a 100644
--- a/default.nix
+++ b/default.nix
@@ -15,4 +15,5 @@ stdenv.mkDerivation {
   checkInputs = [ term-test ];
   inherit doCheck;
   passthru = { direnvrc = ./direnvrc; };
+  preferLocalBuild = true;
 }