diff --git a/cat/cat.rs b/cat/cat.rs
index e87301efc..e8a3348a9 100644
--- a/cat/cat.rs
+++ b/cat/cat.rs
@@ -1,4 +1,5 @@
 #[link(name="cat", vers="1.0.0", author="Seldaek")];
+#[feature(managed_boxes)]
 
 /*
  * This file is part of the uutils coreutils package.