diff --git a/library/core/src/marker.rs b/library/core/src/marker.rs
index f113f939230..9326aaf5684 100644
--- a/library/core/src/marker.rs
+++ b/library/core/src/marker.rs
@@ -291,6 +291,7 @@ pub trait StructuralEq {
 ///
 /// ```
 /// # #[allow(dead_code)]
+/// #[derive(Copy, Clone)]
 /// struct Point {
 ///    x: i32,
 ///    y: i32,