diff --git a/src/Queue.php b/src/Queue.php
index 2287514..52ee135 100644
--- a/src/Queue.php
+++ b/src/Queue.php
@@ -318,9 +318,10 @@ public static function any($concurrency, array $jobs, $handler)
      * $q = new Queue(10, null, array($browser, 'get'));
      * ```
      *
+     * @template TIn
      * @param int                                    $concurrency concurrency soft limit
      * @param int|null                               $limit       queue hard limit or NULL=unlimited
-     * @param callable(mixed):PromiseInterface<T> $handler
+     * @param callable(TIn):PromiseInterface<T> $handler
      * @throws \InvalidArgumentException
      */
     public function __construct($concurrency, $limit, $handler)