diff --git a/.travis.yml b/.travis.yml
index 7894ea3a4..74cd837b0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -27,8 +27,6 @@ after_script:
   - php vendor/bin/coveralls -v
 
 matrix:
-  allow_failures:
-    - php: hhvm
   exclude:
     - php: hhvm
       env: DB=pgsql  # driver currently unsupported by HHVM
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2862Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2862Test.php
index 325a9ad57..28535a3d7 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2862Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC2862Test.php
@@ -2,6 +2,8 @@
 
 namespace Doctrine\Tests\ORM\Functional\Ticket;
 
+use Doctrine\ORM\Tools\ToolsException;
+
 /**
  * @group DDC-2862
  * @group DDC-2183
@@ -18,8 +20,7 @@ class DDC2862Test extends \Doctrine\Tests\OrmFunctionalTestCase
                 $this->_em->getClassMetadata(DDC2862User::CLASSNAME),
                 $this->_em->getClassMetadata(DDC2862Driver::CLASSNAME),
             ));
-        } catch (\Doctrine\ORM\Tools\ToolsException $exc) {
-            $this->assertInstanceOf('Doctrine\DBAL\Exception\TableExistsException', $exc->getPrevious());
+        } catch (ToolsException $exc) {
         }
     }
 
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC742Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC742Test.php
index ad4fad95b..47ba18564 100644
--- a/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC742Test.php
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/DDC742Test.php
@@ -2,6 +2,7 @@
 
 namespace Doctrine\Tests\ORM\Functional\Ticket;
 
+use Doctrine\Common\Cache\FilesystemCache;
 use Doctrine\Common\Collections\ArrayCollection;
 
 /**
@@ -9,27 +10,19 @@ use Doctrine\Common\Collections\ArrayCollection;
  */
 class DDC742Test extends \Doctrine\Tests\OrmFunctionalTestCase
 {
-    private $userCm;
-    private $commentCm;
-
+    /**
+     * {@inheritDoc}
+     */
     protected function setUp()
     {
         parent::setUp();
 
-        if (\extension_loaded('memcache') && @fsockopen('localhost', 11211)) {
-            $memcache = new \Memcache();
-            $memcache->addServer('localhost');
-            $memcache->flush();
+        $testDir = sys_get_temp_dir() . '/DDC742Test' . uniqid();
 
-            $cacheDriver = new \Doctrine\Common\Cache\MemcacheCache();
-            $cacheDriver->setMemcache($memcache);
+        mkdir($testDir);
 
-            $this->_em->getMetadataFactory()->setCacheDriver($cacheDriver);
-        } else if (\extension_loaded('apc')) {
-            $this->_em->getMetadataFactory()->setCacheDriver(new \Doctrine\Common\Cache\ApcCache());
-        } else {
-            $this->markTestSkipped('Test only works with a cache enabled.');
-        }
+        // using a Filesystemcache to ensure that the cached data is serialized
+        $this->_em->getMetadataFactory()->setCacheDriver(new FilesystemCache($testDir));
 
         try {
             $this->_schemaTool->createSchema(array(
@@ -37,7 +30,6 @@ class DDC742Test extends \Doctrine\Tests\OrmFunctionalTestCase
                 $this->_em->getClassMetadata(__NAMESPACE__ . '\DDC742Comment')
             ));
         } catch(\Exception $e) {
-
         }
 
         // make sure classes will be deserialized from caches