diff --git a/src/libarena/lib.rs b/src/libarena/lib.rs
index b40e905620de..9f9ded51e37e 100644
--- a/src/libarena/lib.rs
+++ b/src/libarena/lib.rs
@@ -119,6 +119,11 @@ impl<T> Default for TypedArena<T> {
 }
 
 impl<T> TypedArena<T> {
+    pub fn in_arena(&self, ptr: *const T) -> bool {
+        let ptr = ptr as *const T as *mut T;
+
+        self.chunks.borrow().iter().any(|chunk| chunk.start() <= ptr && ptr < chunk.end())
+    }
     /// Allocates an object in the `TypedArena`, returning a reference to it.
     #[inline]
     pub fn alloc(&self, object: T) -> &mut T {
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index 74fa5363fb2f..6c377941dad1 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -1762,7 +1762,7 @@ nop_list_lift!{Kind<'a> => Kind<'tcx>}
 impl<'a, 'tcx> Lift<'tcx> for &'a mir::interpret::Allocation {
     type Lifted = &'tcx mir::interpret::Allocation;
     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
-        assert!(tcx.global_interners.arena.in_arena(*self as *const _));
+        assert!(tcx.global_arenas.const_allocs.in_arena(*self as *const _));
         Some(unsafe { mem::transmute(*self) })
     }
 }