diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6f6761a..a4cd376 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,15 @@
 # Changelog
 
+## [Unreleased]
+
+### Added
+
+- Internal `Innmind\Time\Halt::asAsync()`
+
+### Deprecated
+
+- `Innmind\Time\Halt::async()`
+
 ## 1.2.0 - 2026-08-09
 
 ### Changed
diff --git a/src/Halt.php b/src/Halt.php
index 32ede9d..70c29db 100644
--- a/src/Halt.php
+++ b/src/Halt.php
@@ -48,6 +48,7 @@ public static function logger(self $self, LoggerInterface $logger): self
 
     /**
      * @internal
+     * @deprecated
      */
     #[\NoDiscard]
     public static function async(Clock $clock): self
@@ -65,4 +66,14 @@ public static function via(callable $via): self
     {
         return new self(Via::of($via));
     }
+
+    /**
+     * @internal
+     * @psalm-mutation-free
+     */
+    #[\NoDiscard]
+    public function asAsync(Clock $clock): self
+    {
+        return new self(Async::of($clock));
+    }
 }
diff --git a/src/Halt/Async.php b/src/Halt/Async.php
index b6d17f4..9a3e257 100644
--- a/src/Halt/Async.php
+++ b/src/Halt/Async.php
@@ -16,6 +16,9 @@
  */
 final class Async implements Implementation
 {
+    /**
+     * @psalm-mutation-free
+     */
     private function __construct(
         private Clock $clock,
     ) {
@@ -33,6 +36,9 @@ public function __invoke(Period $period): Attempt
         return $return->unwrap();
     }
 
+    /**
+     * @psalm-pure
+     */
     #[\NoDiscard]
     public static function of(Clock $clock): self
     {