diff --git a/src/TcpServer.php b/src/TcpServer.php
index 2c0a689e..4b54a815 100644
--- a/src/TcpServer.php
+++ b/src/TcpServer.php
@@ -163,7 +163,7 @@ public function __construct($uri, LoopInterface $loop, array $context = array())
         if (false === $this->master) {
             throw new \RuntimeException('Failed to listen on "' . $uri . '": ' . $errstr, $errno);
         }
-        \stream_set_blocking($this->master, 0);
+        \stream_set_blocking($this->master, false);
 
         $this->resume();
     }