diff --git a/pkgs/by-name/fi/firestarter/package.nix b/pkgs/by-name/fi/firestarter/package.nix
index 96574b71af6e..4ee154b6c3a2 100644
--- a/pkgs/by-name/fi/firestarter/package.nix
+++ b/pkgs/by-name/fi/firestarter/package.nix
@@ -98,9 +98,9 @@ stdenv.mkDerivation rec {
       [ glibc.static ]
   );
 
-  NIX_LDFLAGS = lib.optionals withCuda [
-    "-L${cudatoolkit}/lib/stubs"
-  ];
+  env = lib.optionalAttrs withCuda {
+    NIX_LDFLAGS = "-L${cudatoolkit}/lib/stubs";
+  };
 
   cmakeFlags = [
     "-DFIRESTARTER_BUILD_HWLOC=OFF"