diff --git a/library/core/src/iter/sources/repeat.rs b/library/core/src/iter/sources/repeat.rs
index f578ae86a9fce..197b5f2124235 100644
--- a/library/core/src/iter/sources/repeat.rs
+++ b/library/core/src/iter/sources/repeat.rs
@@ -101,6 +101,11 @@ impl<A: Clone> Iterator for Repeat<A> {
         Some(self.element.clone())
     }
 
+    /// Consumes the iterator and panics.
+    ///
+    /// # Panics
+    ///
+    /// This method always panics because `Repeat` is infinite.
     #[track_caller]
     fn last(self) -> Option<A> {
         panic!("iterator is infinite");