diff --git a/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php b/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php
index c94ace9af9..f16cb4930a 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/ResponseTest.php
@@ -132,8 +132,9 @@ class ResponseTest extends ResponseTestCase
 
     public function testGetDate()
     {
-        $response = new Response('', 200, array('Date' => $this->createDateTimeOneHourAgo()->format(DATE_RFC2822)));
-        $this->assertEquals(0, $this->createDateTimeOneHourAgo()->diff($response->getDate())->format('%s'), '->getDate() returns the Date header if present');
+        $oneHourAgo = $this->createDateTimeOneHourAgo();
+        $response = new Response('', 200, array('Date' => $oneHourAgo->format(DATE_RFC2822)));
+        $this->assertEquals(0, $oneHourAgo->diff($response->getDate())->format('%s'), '->getDate() returns the Date header if present');
 
         $response = new Response();
         $date = $response->getDate();
@@ -142,7 +143,7 @@ class ResponseTest extends ResponseTestCase
         $response = new Response('', 200, array('Date' => $this->createDateTimeOneHourAgo()->format(DATE_RFC2822)));
         $now = $this->createDateTimeNow();
         $response->headers->set('Date', $now->format(DATE_RFC2822));
-        $this->assertEquals(0, $now->diff($response->getDate())->format('%s'), '->getDate() returns the date when the header has been modified');
+        $this->assertLessThanOrEqual(1, $now->diff($response->getDate())->format('%s'), '->getDate() returns the date when the header has been modified');
 
         $response = new Response('', 200);
         $response->headers->remove('Date');
@@ -162,7 +163,7 @@ class ResponseTest extends ResponseTestCase
         $response = new Response();
         $response->headers->set('Cache-Control', 'must-revalidate');
         $response->headers->set('Expires', $this->createDateTimeOneHourLater()->format(DATE_RFC2822));
-        $this->assertEquals(3600, $response->getMaxAge(), '->getMaxAge() falls back to Expires when no max-age or s-maxage directive present');
+        $this->assertLessThanOrEqual(1, $response->getMaxAge() - 3600, '->getMaxAge() falls back to Expires when no max-age or s-maxage directive present');
 
         $response = new Response();
         $response->headers->set('Cache-Control', 'must-revalidate');
@@ -233,7 +234,7 @@ class ResponseTest extends ResponseTestCase
 
         $response = new Response();
         $response->headers->set('Expires', $this->createDateTimeOneHourLater()->format(DATE_RFC2822));
-        $this->assertLessThan(1, 3600 - $response->getTtl(), '->getTtl() uses the Expires header when no max-age is present');
+        $this->assertLessThanOrEqual(1, 3600 - $response->getTtl(), '->getTtl() uses the Expires header when no max-age is present');
 
         $response = new Response();
         $response->headers->set('Expires', $this->createDateTimeOneHourAgo()->format(DATE_RFC2822));
diff --git a/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php b/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php
index 71cdd37aa7..8f54239c69 100644
--- a/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/HttpCache/HttpCacheTest.php
@@ -606,7 +606,7 @@ class HttpCacheTest extends HttpCacheTestCase
         $this->assertTraceContains('miss');
         $this->assertTraceContains('store');
         $this->assertEquals('Hello World', $this->response->getContent());
-        $this->assertRegExp('/s-maxage=2/', $this->response->headers->get('Cache-Control'));
+        $this->assertRegExp('/s-maxage=(?:2|3)/', $this->response->headers->get('Cache-Control'));
 
         $this->request('GET', '/');
         $this->assertHttpKernelIsNotCalled();
diff --git a/src/Symfony/Component/Process/Tests/AbstractProcessTest.php b/src/Symfony/Component/Process/Tests/AbstractProcessTest.php
index 6341d3c6d8..b78c4777be 100644
--- a/src/Symfony/Component/Process/Tests/AbstractProcessTest.php
+++ b/src/Symfony/Component/Process/Tests/AbstractProcessTest.php
@@ -77,9 +77,8 @@ abstract class AbstractProcessTest extends \PHPUnit_Framework_TestCase
         while ($p->isRunning()) {
             usleep(1000);
         }
-        $duration = microtime(true) - $start;
 
-        $this->assertLessThan(1.8, $duration);
+        $this->assertLessThan(4, microtime(true) - $start);
     }
 
     public function testAllOutputIsActuallyReadOnTermination()
@@ -396,7 +395,7 @@ abstract class AbstractProcessTest extends \PHPUnit_Framework_TestCase
         $start = microtime(true);
         $process->start();
         $end = microtime(true);
-        $this->assertLessThan(0.2, $end-$start);
+        $this->assertLessThan(1, $end - $start);
         $process->wait();
     }