diff --git a/src/liballoc/rc.rs b/src/liballoc/rc.rs
index 3080a8bf4596..60a8e1714b64 100644
--- a/src/liballoc/rc.rs
+++ b/src/liballoc/rc.rs
@@ -573,10 +573,11 @@ impl<T: ?Sized> Rc<T> {
     /// Constructs an `Rc` from a raw pointer.
     ///
     /// The raw pointer must have been previously returned by a call to a
-    /// [`Rc::into_raw`][into_raw].
+    /// [`Rc::into_raw`][into_raw] using the same `T`.
     ///
-    /// This function is unsafe because improper use may lead to memory problems. For example, a
-    /// double-free may occur if the function is called twice on the same raw pointer.
+    /// This function is unsafe because improper use may lead to memory unsafety,
+    /// even if `T` is never accessed. For example, a double-free may occur if the function is
+    /// called twice on the same raw pointer.
     ///
     /// [into_raw]: struct.Rc.html#method.into_raw
     ///
diff --git a/src/liballoc/sync.rs b/src/liballoc/sync.rs
index dc53ad284072..024f9407604f 100644
--- a/src/liballoc/sync.rs
+++ b/src/liballoc/sync.rs
@@ -553,10 +553,11 @@ impl<T: ?Sized> Arc<T> {
     /// Constructs an `Arc` from a raw pointer.
     ///
     /// The raw pointer must have been previously returned by a call to a
-    /// [`Arc::into_raw`][into_raw].
+    /// [`Arc::into_raw`][into_raw], using the same `T`.
     ///
-    /// This function is unsafe because improper use may lead to memory problems. For example, a
-    /// double-free may occur if the function is called twice on the same raw pointer.
+    /// This function is unsafe because improper use may lead to memory unsafety,
+    /// even if `T` is never accessed. For example, a double-free may occur if the function is
+    /// called twice on the same raw pointer.
     ///
     /// [into_raw]: struct.Arc.html#method.into_raw
     ///