diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 7957bc35b76b5..c890af631f0a8 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -123,6 +123,7 @@
 #![feature(unsafe_no_drop_flag)]
 #![feature(macro_reexport)]
 #![feature(hash)]
+#![feature(int_uint)]
 #![feature(unique)]
 #![cfg_attr(test, feature(test, rustc_private, env))]