diff --git a/library/core/src/cell.rs b/library/core/src/cell.rs
index fe5dd7be8f6b..7bf32cb0d98f 100644
--- a/library/core/src/cell.rs
+++ b/library/core/src/cell.rs
@@ -1816,6 +1816,8 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 ///
 /// [`.get_mut()`]: `UnsafeCell::get_mut`
 ///
+/// # Memory layout
+///
 /// `UnsafeCell<T>` has the same in-memory representation as its inner type `T`. A consequence
 /// of this guarantee is that it is possible to convert between `T` and `UnsafeCell<T>`.
 /// Special care has to be taken when converting a nested `T` inside of an `Outer<T>` type