diff --git a/test/AwaitTest.php b/test/AwaitTest.php
index b55b61c..8942915 100644
--- a/test/AwaitTest.php
+++ b/test/AwaitTest.php
@@ -20,7 +20,7 @@ public function testExecutionOrder()
 
         $promises[] = React\Async\async(function () use ($deferred) {
             print 'c';
-            $deferred->resolve();
+            $deferred->resolve(null);
             print 'd';
         })();