diff --git a/src/libcore/iter/iterator.rs b/src/libcore/iter/iterator.rs
index 640af748172..0ad29afbade 100644
--- a/src/libcore/iter/iterator.rs
+++ b/src/libcore/iter/iterator.rs
@@ -2358,7 +2358,7 @@ fn sum<S>(self) -> S
     ///
     /// ```
     /// fn factorial(n: u32) -> u32 {
-    ///     (1..).take_while(|&i| i <= n).product()
+    ///     (1..=n).product()
     /// }
     /// assert_eq!(factorial(0), 1);
     /// assert_eq!(factorial(1), 1);