diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index b6b48208ac7b3..e24a3cb898627 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -1460,6 +1460,8 @@ fn _assert_sync_and_send() {
 ///
 /// let count = thread::available_parallelism().map(|n| n.get()).unwrap_or(1);
 /// ```
+#[doc(alias = "hardware_concurrency")] // Alias for C++ `std::thread::hardware_concurrency`.
+#[doc(alias = "available_concurrency")] // Alias for a name we gave this API on unstable.
 #[unstable(feature = "available_parallelism", issue = "74479")]
 pub fn available_parallelism() -> io::Result<NonZeroUsize> {
     imp::available_parallelism()