diff --git a/rust/kernel/alloc/box_ext.rs b/rust/kernel/alloc/box_ext.rs
index b68ade26a42dd0..5b1550d620fd5b 100644
--- a/rust/kernel/alloc/box_ext.rs
+++ b/rust/kernel/alloc/box_ext.rs
@@ -26,9 +26,11 @@ pub trait BoxExt<T>: Sized {
     /// use kernel::alloc::{flags, box_ext::BoxExt};
     /// let value = Box::new([0; 32], flags::GFP_KERNEL)?;
     /// assert_eq!(*value, [0; 32]);
-    /// let value = Box::drop_contents(value);
+    /// let mut value = Box::drop_contents(value);
     /// // Now we can re-use `value`:
-    /// let value = Box::write(value, [1; 32]);
+    /// value.write([1; 32]);
+    /// // SAFETY: We just wrote to it.
+    /// let value = unsafe { value.assume_init() };
     /// assert_eq!(*value, [1; 32]);
     /// # Ok::<(), Error>(())
     /// ```
diff --git a/rust/kernel/rbtree.rs b/rust/kernel/rbtree.rs
index 48ceb9560bf536..25eb36fd1cdceb 100644
--- a/rust/kernel/rbtree.rs
+++ b/rust/kernel/rbtree.rs
@@ -1059,15 +1059,14 @@ impl<K, V> RBTreeNodeReservation<K, V> {
     /// Initialises a node reservation.
     ///
     /// It then becomes an [`RBTreeNode`] that can be inserted into a tree.
-    pub fn into_node(self, key: K, value: V) -> RBTreeNode<K, V> {
-        let node = Box::write(
-            self.node,
-            Node {
-                key,
-                value,
-                links: bindings::rb_node::default(),
-            },
-        );
+    pub fn into_node(mut self, key: K, value: V) -> RBTreeNode<K, V> {
+        self.node.write(Node {
+            key,
+            value,
+            links: bindings::rb_node::default(),
+        });
+        // SAFETY: We just wrote to it.
+        let node = unsafe { self.node.assume_init() };
         RBTreeNode { node }
     }
 }