diff --git a/tst/bootstrap.php b/tst/bootstrap.php
index 5585e79a..f1ba0460 100644
--- a/tst/bootstrap.php
+++ b/tst/bootstrap.php
@@ -1,5 +1,6 @@
 <?php
 error_reporting( E_ALL | E_STRICT );
+ini_set('hhvm.xenon.period', '0');
 
 // change this, if your php files and data is outside of your webservers document root
 if (!defined('PUBLIC_PATH')) define('PUBLIC_PATH', '..');
@@ -256,4 +257,4 @@ class helper
             return var_export($var, $return);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tst/trafficlimiter.php b/tst/trafficlimiter.php
index 94c41e67..548f7f2b 100644
--- a/tst/trafficlimiter.php
+++ b/tst/trafficlimiter.php
@@ -24,9 +24,9 @@ class trafficlimiterTest extends PHPUnit_Framework_TestCase
         trafficlimiter::setLimit(4);
         $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
         $this->assertTrue(trafficlimiter::canPass(), 'first request may pass');
-        sleep(2);
+        sleep(1);
         $this->assertFalse(trafficlimiter::canPass(), 'second request is to fast, may not pass');
-        sleep(3);
+        sleep(4);
         $this->assertTrue(trafficlimiter::canPass(), 'third request waited long enough and may pass');
         $_SERVER['REMOTE_ADDR'] = '2001:1620:2057:dead:beef::cafe:babe';
         $this->assertTrue(trafficlimiter::canPass(), 'fourth request has different ip and may pass');
diff --git a/tst/zerobin.php b/tst/zerobin.php
index 8b865fd8..9b5af64b 100644
--- a/tst/zerobin.php
+++ b/tst/zerobin.php
@@ -124,7 +124,9 @@ class zerobinTest extends PHPUnit_Framework_TestCase
             $file = PATH . $dir . DIRECTORY_SEPARATOR . '.htaccess';
             @unlink($file);
         }
+        ob_start();
         new zerobin;
+        ob_end_clean();
         foreach ($dirs as $dir) {
             $file = PATH . $dir . DIRECTORY_SEPARATOR . '.htaccess';
             $this->assertFileExists(
@@ -145,7 +147,7 @@ class zerobinTest extends PHPUnit_Framework_TestCase
         file_put_contents(CONF, '');
         ob_start();
         new zerobin;
-        $content = ob_get_contents();
+        ob_end_clean();
     }
 
     /**
@@ -185,6 +187,7 @@ class zerobinTest extends PHPUnit_Framework_TestCase
         $_SERVER['HTTP_X_REQUESTED_WITH'] = 'JSONHttpRequest';
         $_SERVER['REQUEST_METHOD'] = 'POST';
         $_SERVER['REMOTE_ADDR'] = '::1';
+        trafficlimiter::setLimit(30);
         trafficlimiter::canPass();
         ob_start();
         new zerobin;
@@ -312,6 +315,7 @@ class zerobinTest extends PHPUnit_Framework_TestCase
         $_SERVER['HTTP_X_REQUESTED_WITH'] = 'JSONHttpRequest';
         $_SERVER['REQUEST_METHOD'] = 'POST';
         $_SERVER['REMOTE_ADDR'] = '::1';
+        $time = time();
         ob_start();
         new zerobin;
         $content = ob_get_contents();
@@ -324,7 +328,7 @@ class zerobinTest extends PHPUnit_Framework_TestCase
         );
         $this->assertTrue($this->_model->exists($response['id']), 'paste exists after posting data');
         $paste = $this->_model->read($response['id']);
-        $this->assertEquals(time() + 300, $paste->meta->expire_date, 'time is set correctly');
+        $this->assertEquals($time + 300, $paste->meta->expire_date, 'time is set correctly');
         $this->assertEquals(1, $paste->meta->opendiscussion, 'time is set correctly');
     }