diff --git a/src/cursor.rs b/src/cursor.rs
index 3261640..9b799b8 100644
--- a/src/cursor.rs
+++ b/src/cursor.rs
@@ -1,5 +1,5 @@
 use libc::{c_void, size_t, c_uint};
-use std::{mem, ptr, raw};
+use std::{ptr, slice};
 use std::marker::{PhantomData, PhantomFn};
 
 use database::Database;
@@ -206,10 +206,7 @@ unsafe fn slice_to_val(slice: Option<&[u8]>) -> ffi::MDB_val {
 }
 
 unsafe fn val_to_slice<'a>(val: ffi::MDB_val) -> &'a [u8] {
-    mem::transmute(raw::Slice {
-        data: val.mv_data as *const u8,
-        len: val.mv_size as usize
-    })
+    slice::from_raw_parts(val.mv_data as *const u8, val.mv_size as usize)
 }
 
 pub struct Iter<'txn> {
diff --git a/src/lib.rs b/src/lib.rs
index 4886467..06dc2f4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,7 +1,7 @@
 //! Idiomatic and safe APIs for interacting with the
 //! [Symas Lightning Memory-Mapped Database (LMDB)](http://symas.com/mdb/).
 
-#![feature(core, libc, optin_builtin_traits, unsafe_destructor)]
+#![feature(libc, optin_builtin_traits, unsafe_destructor)]
 #![cfg_attr(test, feature(std_misc, test))]
 
 extern crate libc;
diff --git a/src/transaction.rs b/src/transaction.rs
index 7e74130..cf045ee 100644
--- a/src/transaction.rs
+++ b/src/transaction.rs
@@ -1,5 +1,5 @@
 use libc::{c_uint, c_void, size_t};
-use std::{mem, ptr, raw};
+use std::{mem, ptr, slice};
 use std::marker::{PhantomData, PhantomFn} ;
 
 use ffi;
@@ -77,10 +77,8 @@ pub trait TransactionExt<'env> : Transaction<'env> + Sized {
         unsafe {
             match ffi::mdb_get(self.txn(), database.dbi(), &mut key_val, &mut data_val) {
                 ffi::MDB_SUCCESS => {
-                    Ok(mem::transmute(raw::Slice {
-                        data: data_val.mv_data as *const u8,
-                        len: data_val.mv_size as usize
-                    }))
+                    Ok(slice::from_raw_parts(data_val.mv_data as *const u8,
+                                             data_val.mv_size as usize))
                 },
                 err_code => Err(Error::from_err_code(err_code)),
             }
@@ -290,10 +288,8 @@ impl <'env> RwTransaction<'env> {
                                           &mut key_val,
                                           &mut data_val,
                                           flags.bits() | ffi::MDB_RESERVE)));
-            Ok(mem::transmute(raw::Slice {
-                data: data_val.mv_data as *const u8,
-                len: data_val.mv_size as usize
-            }))
+            Ok(slice::from_raw_parts_mut(data_val.mv_data as *mut u8,
+                                         data_val.mv_size as usize))
         }
     }