diff --git a/src/liballoc/arc.rs b/src/liballoc/arc.rs
index 0cfdcd2413fd9..3afc34be2cac8 100644
--- a/src/liballoc/arc.rs
+++ b/src/liballoc/arc.rs
@@ -103,7 +103,7 @@ use heap::deallocate;
 /// use std::thread;
 ///
 /// fn main() {
-///     let numbers: Vec<_> = (0..100u32).map(|i| i as f32).collect();
+///     let numbers: Vec<_> = (0..100u32).collect();
 ///     let shared_numbers = Arc::new(numbers);
 ///
 ///     for _ in 0..10 {