diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 1ae4cf8e5ef5..26eae84dee81 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -92,6 +92,7 @@
 #![feature(question_mark)]
 #![feature(never_type)]
 #![feature(prelude_import)]
+#![feature(ordering_chaining)]
 
 #[prelude_import]
 #[allow(unused)]