diff --git a/src/FiberMap.php b/src/FiberMap.php
index 36846b4..ac791a9 100644
--- a/src/FiberMap.php
+++ b/src/FiberMap.php
@@ -9,20 +9,13 @@
  */
 final class FiberMap
 {
-    private static array $status = [];
-    private static array $map   = [];
+    private static array $map = [];
 
     public static function register(\Fiber $fiber): void
     {
-        self::$status[\spl_object_id($fiber)] = false;
         self::$map[\spl_object_id($fiber)] = [];
     }
 
-    public static function cancel(\Fiber $fiber): void
-    {
-        self::$status[\spl_object_id($fiber)] = true;
-    }
-
     public static function setPromise(\Fiber $fiber, PromiseInterface $promise): void
     {
         self::$map[\spl_object_id($fiber)] = $promise;
@@ -40,6 +33,6 @@ public static function getPromise(\Fiber $fiber): ?PromiseInterface
 
     public static function unregister(\Fiber $fiber): void
     {
-        unset(self::$status[\spl_object_id($fiber)], self::$map[\spl_object_id($fiber)]);
+        unset(self::$map[\spl_object_id($fiber)]);
     }
 }
diff --git a/src/functions.php b/src/functions.php
index 092115b..9759fd3 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -199,7 +199,6 @@ function async(callable $function): callable
 
             $fiber->start();
         }, function () use (&$fiber): void {
-            FiberMap::cancel($fiber);
             $promise = FiberMap::getPromise($fiber);
             if ($promise instanceof PromiseInterface && \method_exists($promise, 'cancel')) {
                 $promise->cancel();