1 files changed, 3 insertions, 1 deletions
diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index fda103a52d8..c381998d99a 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -137,9 +137,11 @@
 //! use std::cell::Cell;
 //! use std::ptr::NonNull;
 //! use std::intrinsics::abort;
+//! use std::marker::PhantomData;
 //!
 //! struct Rc<T: ?Sized> {
-//!     ptr: NonNull<RcBox<T>>
+//!     ptr: NonNull<RcBox<T>>,
+//!     phantom: PhantomData<RcBox<T>>,
 //! }
 //!
 //! struct RcBox<T: ?Sized> {