diff --git a/src/libcore/cleanup.rs b/src/libcore/cleanup.rs
index 6912d6d995b8..393a71562ad0 100644
--- a/src/libcore/cleanup.rs
+++ b/src/libcore/cleanup.rs
@@ -154,7 +154,7 @@ fn debug_mem() -> bool {
 #[cfg(notest)]
 #[lang="annihilate"]
 pub unsafe fn annihilate() {
-    use rt::local_free;
+    use unstable::lang::local_free;
     use io::WriterUtil;
     use io;
     use libc;
diff --git a/src/libcore/core.rc b/src/libcore/core.rc
index 525887f8cb33..c8d2da28255f 100644
--- a/src/libcore/core.rc
+++ b/src/libcore/core.rc
@@ -225,8 +225,6 @@ pub const debug : u32 = 4_u32;
 
 /* Unsupported interfaces */
 
-// The runtime interface used by the compiler
-#[cfg(notest)] pub mod rt;
 // Private APIs
 pub mod unstable;
 // NOTE: Remove after snapshot
diff --git a/src/libcore/task/local_data_priv.rs b/src/libcore/task/local_data_priv.rs
index df5a5af74cab..fc1527653228 100644
--- a/src/libcore/task/local_data_priv.rs
+++ b/src/libcore/task/local_data_priv.rs
@@ -19,11 +19,7 @@ use prelude::*;
 use task::rt;
 use task::local_data::LocalDataKey;
 
-#[cfg(notest)]
-use rt::rust_task;
-#[cfg(test)]
-#[allow(non_camel_case_types)]
-type rust_task = libc::c_void;
+use super::rt::rust_task;
 
 pub trait LocalData { }
 impl<T:Durable> LocalData for @T { }
diff --git a/src/libcore/unstable.rs b/src/libcore/unstable.rs
index b7b4b5634252..8c0c029a90fc 100644
--- a/src/libcore/unstable.rs
+++ b/src/libcore/unstable.rs
@@ -36,6 +36,9 @@ pub mod exchange_alloc;
 pub mod intrinsics;
 #[path = "unstable/extfmt.rs"]
 pub mod extfmt;
+#[path = "unstable/lang.rs"]
+#[cfg(notest)]
+pub mod lang;
 
 extern mod rustrt {
     pub unsafe fn rust_create_little_lock() -> rust_little_lock;
diff --git a/src/libcore/rt.rs b/src/libcore/unstable/lang.rs
similarity index 98%
rename from src/libcore/rt.rs
rename to src/libcore/unstable/lang.rs
index a4f90e37683e..e74052995e6c 100644
--- a/src/libcore/rt.rs
+++ b/src/libcore/unstable/lang.rs
@@ -20,9 +20,6 @@ use cast::transmute;
 
 use gc::{cleanup_stack_for_failure, gc, Word};
 
-#[allow(non_camel_case_types)]
-pub type rust_task = c_void;
-
 #[cfg(target_word_size = "32")]
 pub const FROZEN_BIT: uint = 0x80000000;
 #[cfg(target_word_size = "64")]