diff --git a/src/liballoc/tests/lib.rs b/src/liballoc/tests/lib.rs
index 676874c8b27df..79e5ba340b784 100644
--- a/src/liballoc/tests/lib.rs
+++ b/src/liballoc/tests/lib.rs
@@ -3,7 +3,6 @@
 #![feature(drain_filter)]
 #![feature(exact_size_is_empty)]
 #![feature(new_uninit)]
-#![feature(option_flattening)]
 #![feature(pattern)]
 #![feature(trusted_len)]
 #![feature(try_reserve)]
diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index 89f2d7ab29c93..f0ac5e749f6b3 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -1567,7 +1567,6 @@ impl<T> Option<Option<T>> {
     /// # Examples
     /// Basic usage:
     /// ```
-    /// #![feature(option_flattening)]
     /// let x: Option<Option<u32>> = Some(Some(6));
     /// assert_eq!(Some(6), x.flatten());
     ///
@@ -1579,13 +1578,12 @@ impl<T> Option<Option<T>> {
     /// ```
     /// Flattening once only removes one level of nesting:
     /// ```
-    /// #![feature(option_flattening)]
     /// let x: Option<Option<Option<u32>>> = Some(Some(Some(6)));
     /// assert_eq!(Some(Some(6)), x.flatten());
     /// assert_eq!(Some(6), x.flatten().flatten());
     /// ```
     #[inline]
-    #[unstable(feature = "option_flattening", issue = "60258")]
+    #[stable(feature = "option_flattening", since = "1.40.0")]
     pub fn flatten(self) -> Option<T> {
         self.and_then(convert::identity)
     }