diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index b76d3b84254..a0cadd6fc72 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -24,3 +24,4 @@
 /* Core modules for ownership management */
 
 pub mod intrinsics;
+pub mod mem;
diff --git a/src/libstd/mem.rs b/src/libcore/mem.rs
similarity index 99%
rename from src/libstd/mem.rs
rename to src/libcore/mem.rs
index d216d91b901..860304232d4 100644
--- a/src/libstd/mem.rs
+++ b/src/libcore/mem.rs
@@ -13,8 +13,6 @@
 //! This module contains functions for querying the size and alignment of
 //! types, initializing and manipulating memory.
 
-#![allow(missing_doc)] // FIXME
-
 use cast;
 use ptr;
 use intrinsics;
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 2c971542960..9ef657f6e4a 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -134,6 +134,7 @@ extern crate core;
 #[cfg(test)] pub use owned = realstd::owned;
 
 pub use core::intrinsics;
+pub use core::mem;
 
 // Run tests with libgreen instead of libnative.
 //
@@ -243,8 +244,6 @@ pub mod path;
 pub mod cast;
 pub mod fmt;
 pub mod cleanup;
-pub mod mem;
-
 
 /* Unsupported interfaces */