diff --git a/src/libarena/lib.rs b/src/libarena/lib.rs
index c4c1635aa2a..4338ac7fd02 100644
--- a/src/libarena/lib.rs
+++ b/src/libarena/lib.rs
@@ -32,6 +32,7 @@
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(generic_param_attrs)]
+#![feature(needs_drop)]
 #![cfg_attr(stage0, feature(staged_api))]
 #![cfg_attr(test, feature(test))]
 
@@ -82,7 +83,7 @@ impl<T> TypedArenaChunk<T> {
     unsafe fn destroy(&mut self, len: usize) {
         // The branch on needs_drop() is an -O1 performance optimization.
         // Without the branch, dropping TypedArena<u8> takes linear time.
-        if intrinsics::needs_drop::<T>() {
+        if mem::needs_drop::<T>() {
             let mut start = self.start();
             // Destroy all allocated objects.
             for _ in 0..len {
@@ -350,7 +351,7 @@ impl DroplessArena {
     #[inline]
     pub fn alloc<T>(&self, object: T) -> &mut T {
         unsafe {
-            assert!(!intrinsics::needs_drop::<T>());
+            assert!(!mem::needs_drop::<T>());
             assert!(mem::size_of::<T>() != 0);
 
             self.align_for::<T>();
@@ -379,9 +380,7 @@ impl DroplessArena {
     #[inline]
     pub fn alloc_slice<T>(&self, slice: &[T]) -> &mut [T]
         where T: Copy {
-        unsafe {
-            assert!(!intrinsics::needs_drop::<T>());
-        }
+        assert!(!mem::needs_drop::<T>());
         assert!(mem::size_of::<T>() != 0);
         assert!(slice.len() != 0);
         self.align_for::<T>();
diff --git a/src/libstd/collections/hash/table.rs b/src/libstd/collections/hash/table.rs
index a15269cc87c..50c721db849 100644
--- a/src/libstd/collections/hash/table.rs
+++ b/src/libstd/collections/hash/table.rs
@@ -12,9 +12,8 @@ use alloc::heap::{allocate, deallocate};
 
 use cmp;
 use hash::{BuildHasher, Hash, Hasher};
-use intrinsics::needs_drop;
 use marker;
-use mem::{align_of, size_of};
+use mem::{align_of, size_of, needs_drop};
 use mem;
 use ops::{Deref, DerefMut};
 use ptr::{self, Unique, Shared};
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index a4c3b276efd..b0820d6f05a 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -281,6 +281,7 @@
 #![feature(linkage)]
 #![feature(macro_reexport)]
 #![feature(needs_panic_runtime)]
+#![feature(needs_drop)]
 #![feature(never_type)]
 #![feature(num_bits_bytes)]
 #![feature(old_wrapping)]
diff --git a/src/libstd/sys/redox/fast_thread_local.rs b/src/libstd/sys/redox/fast_thread_local.rs
index f6414673dac..7dc61ce6654 100644
--- a/src/libstd/sys/redox/fast_thread_local.rs
+++ b/src/libstd/sys/redox/fast_thread_local.rs
@@ -12,9 +12,10 @@
 #![unstable(feature = "thread_local_internals", issue = "0")]
 
 use cell::{Cell, UnsafeCell};
-use intrinsics;
+use mem;
 use ptr;
 
+
 pub struct Key<T> {
     inner: UnsafeCell<Option<T>>,
 
@@ -37,7 +38,7 @@ impl<T> Key<T> {
 
     pub fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
         unsafe {
-            if intrinsics::needs_drop::<T>() && self.dtor_running.get() {
+            if mem::needs_drop::<T>() && self.dtor_running.get() {
                 return None
             }
             self.register_dtor();
@@ -46,7 +47,7 @@ impl<T> Key<T> {
     }
 
     unsafe fn register_dtor(&self) {
-        if !intrinsics::needs_drop::<T>() || self.dtor_registered.get() {
+        if !mem::needs_drop::<T>() || self.dtor_registered.get() {
             return
         }
 
diff --git a/src/libstd/sys/unix/fast_thread_local.rs b/src/libstd/sys/unix/fast_thread_local.rs
index 07d76a93dd1..6b3973de84c 100644
--- a/src/libstd/sys/unix/fast_thread_local.rs
+++ b/src/libstd/sys/unix/fast_thread_local.rs
@@ -13,7 +13,7 @@
 
 use cell::{Cell, UnsafeCell};
 use fmt;
-use intrinsics;
+use mem;
 use ptr;
 
 pub struct Key<T> {
@@ -44,7 +44,7 @@ impl<T> Key<T> {
 
     pub fn get(&'static self) -> Option<&'static UnsafeCell<Option<T>>> {
         unsafe {
-            if intrinsics::needs_drop::<T>() && self.dtor_running.get() {
+            if mem::needs_drop::<T>() && self.dtor_running.get() {
                 return None
             }
             self.register_dtor();
@@ -53,7 +53,7 @@ impl<T> Key<T> {
     }
 
     unsafe fn register_dtor(&self) {
-        if !intrinsics::needs_drop::<T>() || self.dtor_registered.get() {
+        if !mem::needs_drop::<T>() || self.dtor_registered.get() {
             return
         }