3 files changed, 5 insertions, 3 deletions
diff --git a/src/libsync/atomic.rs b/src/libsync/atomic.rs
index 301d444b1b1..cd7102a756a 100644
--- a/src/libsync/atomic.rs
+++ b/src/libsync/atomic.rs
@@ -103,10 +103,9 @@
 
 #![allow(deprecated)]
 
-use core::prelude::*;
-
 use alloc::boxed::Box;
 use core::mem;
+use core::prelude::{Drop, None, Option, Some};
 
 pub use core::atomic::{AtomicBool, AtomicInt, AtomicUint, AtomicPtr};
 pub use core::atomic::{Ordering, Relaxed, Release, Acquire, AcqRel, SeqCst};
diff --git a/src/libsync/comm/sync.rs b/src/libsync/comm/sync.rs
index aef02f654c1..1ee9fef1918 100644
--- a/src/libsync/comm/sync.rs
+++ b/src/libsync/comm/sync.rs
@@ -37,7 +37,6 @@ use core::prelude::*;
 
 use alloc::boxed::Box;
 use collections::Vec;
-use collections::Collection;
 use core::mem;
 use core::cell::UnsafeCell;
 use rustrt::local::Local;
diff --git a/src/libsync/lib.rs b/src/libsync/lib.rs
index de98f79093e..bed90743503 100644
--- a/src/libsync/lib.rs
+++ b/src/libsync/lib.rs
@@ -28,9 +28,13 @@
        html_playground_url = "http://play.rust-lang.org/")]
 
 #![feature(phase, globs, macro_rules, unsafe_destructor)]
+#![feature(import_shadowing)]
 #![deny(missing_doc)]
 #![no_std]
 
+// NOTE(stage0, pcwalton): Remove after snapshot.
+#![allow(unknown_features)]
+
 #[phase(plugin, link)] extern crate core;
 extern crate alloc;
 extern crate collections;