diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs
index 4b8ea708e7e57..010d17f74762c 100644
--- a/library/alloc/src/rc.rs
+++ b/library/alloc/src/rc.rs
@@ -3004,7 +3004,6 @@ pub struct Weak<
     // `Weak::new` sets this to `usize::MAX` so that it doesn’t need
     // to allocate space on the heap. That's not a value a real pointer
     // will ever have because RcInner has alignment at least 2.
-    // This is only possible when `T: Sized`; unsized `T` never dangle.
     ptr: NonNull<RcInner<T>>,
     alloc: A,
 }
diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs
index 17090925cfa0c..1e3c03977bd75 100644
--- a/library/alloc/src/sync.rs
+++ b/library/alloc/src/sync.rs
@@ -342,7 +342,6 @@ pub struct Weak<
     // `Weak::new` sets this to `usize::MAX` so that it doesn’t need
     // to allocate space on the heap. That's not a value a real pointer
     // will ever have because RcInner has alignment at least 2.
-    // This is only possible when `T: Sized`; unsized `T` never dangle.
     ptr: NonNull<ArcInner<T>>,
     alloc: A,
 }