diff --git a/tests/FunctionResolveTest.php b/tests/FunctionResolveTest.php
index 1bc7da2..0bfdc21 100644
--- a/tests/FunctionResolveTest.php
+++ b/tests/FunctionResolveTest.php
@@ -50,7 +50,7 @@ public function testCancellingPromiseWillCancelLoopTimer()
     {
         $loop = $this->getMockBuilder('React\EventLoop\LoopInterface')->getMock();
 
-        $timer = $this->getMockBuilder('React\EventLoop\Timer\TimerInterface')->getMock();
+        $timer = $this->getMockBuilder(interface_exists('React\EventLoop\TimerInterface') ? 'React\EventLoop\TimerInterface' : 'React\EventLoop\Timer\TimerInterface')->getMock();
         $loop->expects($this->once())->method('addTimer')->will($this->returnValue($timer));
 
         $promise = Timer\resolve(0.01, $loop);