1 files changed, 2 insertions, 2 deletions
diff --git a/src/liballoc/arc.rs b/src/liballoc/arc.rs
index e060ecad974..4810e15d68b 100644
--- a/src/liballoc/arc.rs
+++ b/src/liballoc/arc.rs
@@ -129,9 +129,9 @@ pub struct Weak<T> {
     _ptr: *mut ArcInner<T>,
 }
 
-impl<T: Sync + Send> Send for Arc<T> { }
+unsafe impl<T: Sync + Send> Send for Arc<T> { }
 
-impl<T: Sync + Send> Sync for Arc<T> { }
+unsafe impl<T: Sync + Send> Sync for Arc<T> { }
 
 struct ArcInner<T> {
     strong: atomic::AtomicUint,