diff --git a/components/script/lib.rs b/components/script/lib.rs
index 2b9c5b8d15f6..0e63fef2a02b 100644
--- a/components/script/lib.rs
+++ b/components/script/lib.rs
@@ -15,7 +15,6 @@
 #![feature(plugin)]
 #![feature(proc_macro)]
 #![feature(try_from)]
-#![feature(untagged_unions)]
 
 #![deny(unsafe_code)]
 #![allow(non_snake_case)]