diff --git a/pkgs/by-name/fu/fuc/package.nix b/pkgs/by-name/fu/fuc/package.nix
index 6175f66772b3..bb6632c0f710 100644
--- a/pkgs/by-name/fu/fuc/package.nix
+++ b/pkgs/by-name/fu/fuc/package.nix
@@ -19,7 +19,7 @@ rustPlatform.buildRustPackage (finalAttrs: {
 
   cargoHash = "sha256-OoTWGeF96BpPDx1Y9AEVOIBK7kCz6pjw24pLiNcKmOc=";
 
-  RUSTC_BOOTSTRAP = 1;
+  env.RUSTC_BOOTSTRAP = 1;
 
   cargoBuildFlags = [
     "--workspace"