diff --git a/src/lib.rs b/src/lib.rs
index cdbfbd7..cfbffba 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -44,15 +44,13 @@
 //!
 //! [newt]: https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method
 
-#![feature(slicing_syntax, core)]
+#![feature(slicing_syntax, collections, core, hash, rand, std_misc)]
 #![cfg_attr(test, deny(warnings))]
 #![doc(html_logo_url = "http://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
        html_favicon_url = "http://www.rust-lang.org/favicon.ico",
        html_root_url = "http://doc.rust-lang.org/num/",
        html_playground_url = "http://play.rust-lang.org/")]
 
-#![allow(unstable)]
-
 extern crate "rustc-serialize" as rustc_serialize;
 extern crate core;