diff --git a/src/Assert/AssertCaseTrait.php b/src/Assert/AssertCaseTrait.php
index eb865bd..f416404 100644
--- a/src/Assert/AssertCaseTrait.php
+++ b/src/Assert/AssertCaseTrait.php
@@ -4,8 +4,6 @@
 
 namespace Asynit\Assert;
 
-use Asynit\Attribute\OnCreate;
-use Asynit\Test;
 use bovigo\assert\predicate\Predicate;
 
 use function bovigo\assert\counting;
@@ -50,14 +48,6 @@
 
 trait AssertCaseTrait
 {
-    protected Test $test;
-
-    #[OnCreate]
-    public function setUpTest(Test $test): void
-    {
-        $this->test = $test;
-    }
-
     /**
      * Asserts that an array has a specified key.
      *
@@ -535,7 +525,7 @@ public function assertContainsSubset(array $other, array $subset, bool $strict =
 
     public function assert($value, callable $predicate, ?string $description = null): bool
     {
-        return (new Assertion($value, exporter(), $this->test))
+        return (new Assertion($value, exporter()))
             ->evaluate(counting(Predicate::castFrom($predicate)), $description);
     }
 
diff --git a/src/Assert/Assertion.php b/src/Assert/Assertion.php
index 8c9e2b1..93937af 100644
--- a/src/Assert/Assertion.php
+++ b/src/Assert/Assertion.php
@@ -4,6 +4,7 @@
 
 namespace Asynit\Assert;
 
+use Asynit\Runner\TestStorage;
 use Asynit\Test;
 use bovigo\assert\Assertion as BaseAssertion;
 use bovigo\assert\AssertionFailure;
@@ -16,18 +17,15 @@ class Assertion extends BaseAssertion
 
     private Exporter $exporter;
 
-    private Test $test;
-
     /**
      * constructor.
      */
-    public function __construct($value, Exporter $exporter, Test $test)
+    public function __construct($value, Exporter $exporter)
     {
         parent::__construct($value, $exporter);
 
         $this->value = $value;
         $this->exporter = $exporter;
-        $this->test = $test;
     }
 
     public function evaluate(Predicate $predicate, ?string $description = null): bool
@@ -50,7 +48,7 @@ public function evaluate(Predicate $predicate, ?string $description = null): boo
             throw new AssertionFailure($message);
         }
 
-        $this->test->addAssertion($this->describeSuccess($predicate, $description));
+        TestStorage::get()?->addAssertion($this->describeSuccess($predicate, $description));
 
         return $result;
     }
diff --git a/src/Runner/PoolRunner.php b/src/Runner/PoolRunner.php
index 0eb61ce..6167653 100644
--- a/src/Runner/PoolRunner.php
+++ b/src/Runner/PoolRunner.php
@@ -46,6 +46,8 @@ public function loop(Pool $pool): void
 
             $futures[$test->getIdentifier()] = async(function () use ($test, &$futures) {
                 $lock = $this->semaphore->acquire();
+                TestStorage::set($test);
+
                 $this->run($test);
                 $lock->release();
 
@@ -100,7 +102,7 @@ private function getTestCase(Test $test): object
                     continue;
                 }
 
-                $testCase->{$reflectionMethod->getName()}($test);
+                $testCase->{$reflectionMethod->getName()}();
             }
 
             $this->testCases[$reflectionClass->getName()] = $testCase;
diff --git a/src/Runner/TestStorage.php b/src/Runner/TestStorage.php
new file mode 100644
index 0000000..2ad275a
--- /dev/null
+++ b/src/Runner/TestStorage.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace Asynit\Runner;
+
+use Asynit\Test;
+
+/** @internal */
+final class TestStorage
+{
+    private static ?\WeakMap $localStorage = null;
+
+    public static function set(Test $test): void
+    {
+        $fiber = \Fiber::getCurrent();
+
+        if (null === $fiber) {
+            return;
+        }
+
+        self::$localStorage ??= new \WeakMap();
+        self::$localStorage[$fiber] = $test;
+    }
+
+    public static function get(): ?Test
+    {
+        $fiber = \Fiber::getCurrent();
+
+        if (null === $fiber) {
+            return null;
+        }
+
+        self::$localStorage ??= new \WeakMap();
+
+        return self::$localStorage[$fiber] ?? null;
+    }
+}