diff --git a/pkgs/by-name/sh/shadow-tls/package.nix b/pkgs/by-name/sh/shadow-tls/package.nix
index 960372fdf6b5..f985456e6329 100644
--- a/pkgs/by-name/sh/shadow-tls/package.nix
+++ b/pkgs/by-name/sh/shadow-tls/package.nix
@@ -17,7 +17,7 @@ rustPlatform.buildRustPackage rec {
 
   cargoHash = "sha256-1oJCdqBa1pWpQ7QvZ0vZaOd73R+SzR9OPf+yoI+RwCY=";
 
-  RUSTC_BOOTSTRAP = 1;
+  env.RUSTC_BOOTSTRAP = 1;
 
   # network required
   doCheck = false;