diff --git a/tests/Composer/Test/AllFunctionalTest.php b/tests/Composer/Test/AllFunctionalTest.php
index df8ddf185..7ef3aa0af 100644
--- a/tests/Composer/Test/AllFunctionalTest.php
+++ b/tests/Composer/Test/AllFunctionalTest.php
@@ -12,14 +12,15 @@
 
 namespace Composer\Test;
 
-use Symfony\Component\Process\Process;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 use Symfony\Component\Finder\Finder;
+use Symfony\Component\Process\Process;
 
 /**
  * @group slow
  */
-class AllFunctionalTest extends \PHPUnit_Framework_TestCase
+class AllFunctionalTest extends TestCase
 {
     protected $oldcwd;
     protected $oldenv;
@@ -29,17 +30,21 @@ class AllFunctionalTest extends \PHPUnit_Framework_TestCase
     public function setUp()
     {
         $this->oldcwd = getcwd();
+
         chdir(__DIR__.'/Fixtures/functional');
     }
 
     public function tearDown()
     {
         chdir($this->oldcwd);
+
         $fs = new Filesystem;
+
         if ($this->testDir) {
             $fs->removeDirectory($this->testDir);
             $this->testDir = null;
         }
+
         if ($this->oldenv) {
             $fs->removeDirectory(getenv('COMPOSER_HOME'));
             $_SERVER['COMPOSER_HOME'] = $this->oldenv;
@@ -50,7 +55,7 @@ class AllFunctionalTest extends \PHPUnit_Framework_TestCase
 
     public static function setUpBeforeClass()
     {
-        self::$pharPath = sys_get_temp_dir().'/composer-phar-test/composer.phar';
+        self::$pharPath = self::getUniqueTmpDirectory() . '/composer.phar';
     }
 
     public static function tearDownAfterClass()
@@ -66,9 +71,7 @@ class AllFunctionalTest extends \PHPUnit_Framework_TestCase
         }
 
         $target = dirname(self::$pharPath);
-        $fs = new Filesystem;
-        $fs->removeDirectory($target);
-        $fs->ensureDirectoryExists($target);
+        $fs = new Filesystem();
         chdir($target);
 
         $it = new \RecursiveDirectoryIterator(__DIR__.'/../../../', \RecursiveDirectoryIterator::SKIP_DOTS);
@@ -85,9 +88,11 @@ class AllFunctionalTest extends \PHPUnit_Framework_TestCase
 
         $proc = new Process('php '.escapeshellarg('./bin/compile'), $target);
         $exitcode = $proc->run();
+
         if ($exitcode !== 0 || trim($proc->getOutput())) {
             $this->fail($proc->getOutput());
         }
+
         $this->assertTrue(file_exists(self::$pharPath));
     }
 
@@ -140,7 +145,7 @@ class AllFunctionalTest extends \PHPUnit_Framework_TestCase
         $data = array();
         $section = null;
 
-        $testDir = sys_get_temp_dir().'/composer_functional_test'.uniqid(mt_rand(), true);
+        $testDir = self::getUniqueTmpDirectory();
         $this->testDir = $testDir;
         $varRegex = '#%([a-zA-Z_-]+)%#';
         $variableReplacer = function ($match) use (&$data, $testDir) {
diff --git a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
index 502a483ab..07706c5d2 100644
--- a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
+++ b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
@@ -88,8 +88,7 @@ class AutoloadGeneratorTest extends TestCase
         $this->fs = new Filesystem;
         $that = $this;
 
-        $this->workingDir = realpath(sys_get_temp_dir()).DIRECTORY_SEPARATOR.'cmptest-'.md5(uniqid('', true));
-        $this->fs->ensureDirectoryExists($this->workingDir);
+        $this->workingDir = $this->getUniqueTmpDirectory();
         $this->vendorDir = $this->workingDir.DIRECTORY_SEPARATOR.'composer-test-autoload';
         $this->ensureDirectoryExistsAndClear($this->vendorDir);
 
@@ -144,6 +143,7 @@ class AutoloadGeneratorTest extends TestCase
         if (is_dir($this->workingDir)) {
             $this->fs->removeDirectory($this->workingDir);
         }
+
         if (is_dir($this->vendorDir)) {
             $this->fs->removeDirectory($this->vendorDir);
         }
diff --git a/tests/Composer/Test/Autoload/ClassMapGeneratorTest.php b/tests/Composer/Test/Autoload/ClassMapGeneratorTest.php
index 3b703d8f3..cd3d43260 100644
--- a/tests/Composer/Test/Autoload/ClassMapGeneratorTest.php
+++ b/tests/Composer/Test/Autoload/ClassMapGeneratorTest.php
@@ -19,10 +19,11 @@
 namespace Composer\Test\Autoload;
 
 use Composer\Autoload\ClassMapGenerator;
+use Composer\TestCase;
 use Symfony\Component\Finder\Finder;
 use Composer\Util\Filesystem;
 
-class ClassMapGeneratorTest extends \PHPUnit_Framework_TestCase
+class ClassMapGeneratorTest extends TestCase
 {
     /**
      * @dataProvider getTestCreateMapTests
@@ -127,10 +128,8 @@ class ClassMapGeneratorTest extends \PHPUnit_Framework_TestCase
     {
         $this->checkIfFinderIsAvailable();
 
-        $tempDir = sys_get_temp_dir().'/ComposerTestAmbiguousRefs';
-        if (!is_dir($tempDir.'/other')) {
-            mkdir($tempDir.'/other', 0777, true);
-        }
+        $tempDir = $this->getUniqueTmpDirectory();
+        $this->ensureDirectoryExistsAndClear($tempDir.'/other');
 
         $finder = new Finder();
         $finder->files()->in($tempDir);
@@ -171,13 +170,9 @@ class ClassMapGeneratorTest extends \PHPUnit_Framework_TestCase
      */
     public function testUnambiguousReference()
     {
-        $tempDir = sys_get_temp_dir().'/ComposerTestUnambiguousRefs';
-        if (!is_dir($tempDir)) {
-            mkdir($tempDir, 0777, true);
-        }
+        $tempDir = $this->getUniqueTmpDirectory();
 
         file_put_contents($tempDir.'/A.php', "<?php\nclass A {}");
-
         file_put_contents(
             $tempDir.'/B.php',
             "<?php
diff --git a/tests/Composer/Test/CacheTest.php b/tests/Composer/Test/CacheTest.php
index 293064598..4e8ed6045 100644
--- a/tests/Composer/Test/CacheTest.php
+++ b/tests/Composer/Test/CacheTest.php
@@ -25,15 +25,15 @@ class CacheTest extends TestCase
             $this->markTestSkipped('Test causes intermittent failures on Travis');
         }
 
-        $this->root = sys_get_temp_dir() . '/composer_testdir';
-        $this->ensureDirectoryExistsAndClear($this->root);
-
+        $this->root = $this->getUniqueTmpDirectory();
         $this->files = array();
         $zeros = str_repeat('0', 1000);
+
         for ($i = 0; $i < 4; $i++) {
             file_put_contents("{$this->root}/cached.file{$i}.zip", $zeros);
             $this->files[] = new \SplFileInfo("{$this->root}/cached.file{$i}.zip");
         }
+
         $this->finder = $this->getMockBuilder('Symfony\Component\Finder\Finder')->disableOriginalConstructor()->getMock();
 
         $io = $this->getMock('Composer\IO\IOInterface');
diff --git a/tests/Composer/Test/Config/JsonConfigSourceTest.php b/tests/Composer/Test/Config/JsonConfigSourceTest.php
index 819f12f2f..5877f69fb 100644
--- a/tests/Composer/Test/Config/JsonConfigSourceTest.php
+++ b/tests/Composer/Test/Config/JsonConfigSourceTest.php
@@ -14,9 +14,10 @@ namespace Composer\Test\Json;
 
 use Composer\Config\JsonConfigSource;
 use Composer\Json\JsonFile;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 
-class JsonConfigSourceTest extends \PHPUnit_Framework_TestCase
+class JsonConfigSourceTest extends TestCase
 {
     /** @var Filesystem */
     private $fs;
@@ -31,8 +32,7 @@ class JsonConfigSourceTest extends \PHPUnit_Framework_TestCase
     protected function setUp()
     {
         $this->fs = new Filesystem;
-        $this->workingDir = realpath(sys_get_temp_dir()).DIRECTORY_SEPARATOR.'cmptest';
-        $this->fs->ensureDirectoryExists($this->workingDir);
+        $this->workingDir = $this->getUniqueTmpDirectory();
     }
 
     protected function tearDown()
diff --git a/tests/Composer/Test/Downloader/FileDownloaderTest.php b/tests/Composer/Test/Downloader/FileDownloaderTest.php
index f0578f6be..9b9f7b671 100644
--- a/tests/Composer/Test/Downloader/FileDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/FileDownloaderTest.php
@@ -13,9 +13,10 @@
 namespace Composer\Test\Downloader;
 
 use Composer\Downloader\FileDownloader;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 
-class FileDownloaderTest extends \PHPUnit_Framework_TestCase
+class FileDownloaderTest extends TestCase
 {
     protected function getDownloader($io = null, $config = null, $eventDispatcher = null, $cache = null, $rfs = null, $filesystem = null)
     {
@@ -53,9 +54,9 @@ class FileDownloaderTest extends \PHPUnit_Framework_TestCase
             ->will($this->returnValue(array('url')))
         ;
 
-        $path = tempnam(sys_get_temp_dir(), 'c');
-
+        $path = tempnam($this->getUniqueTmpDirectory(), 'c');
         $downloader = $this->getDownloader();
+
         try {
             $downloader->download($packageMock, $path);
             $this->fail();
@@ -102,10 +103,7 @@ class FileDownloaderTest extends \PHPUnit_Framework_TestCase
             ->will($this->returnValue(array()))
         ;
 
-        do {
-            $path = sys_get_temp_dir().'/'.md5(time().mt_rand());
-        } while (file_exists($path));
-
+        $path = $this->getUniqueTmpDirectory();
         $ioMock = $this->getMock('Composer\IO\IOInterface');
         $ioMock->expects($this->any())
             ->method('write')
@@ -187,14 +185,9 @@ class FileDownloaderTest extends \PHPUnit_Framework_TestCase
         ;
         $filesystem = $this->getMock('Composer\Util\Filesystem');
 
-        do {
-            $path = sys_get_temp_dir().'/'.md5(time().mt_rand());
-        } while (file_exists($path));
-
+        $path = $this->getUniqueTmpDirectory();
         $downloader = $this->getDownloader(null, null, null, null, null, $filesystem);
-
         // make sure the file expected to be downloaded is on disk already
-        mkdir($path, 0777, true);
         touch($path.'/script.js');
 
         try {
diff --git a/tests/Composer/Test/Downloader/GitDownloaderTest.php b/tests/Composer/Test/Downloader/GitDownloaderTest.php
index f0b6699e5..26437ada5 100644
--- a/tests/Composer/Test/Downloader/GitDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/GitDownloaderTest.php
@@ -14,9 +14,10 @@ namespace Composer\Test\Downloader;
 
 use Composer\Downloader\GitDownloader;
 use Composer\Config;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 
-class GitDownloaderTest extends \PHPUnit_Framework_TestCase
+class GitDownloaderTest extends TestCase
 {
     /** @var Filesystem */
     private $fs;
@@ -26,7 +27,7 @@ class GitDownloaderTest extends \PHPUnit_Framework_TestCase
     protected function setUp()
     {
         $this->fs = new Filesystem;
-        $this->workingDir = realpath(sys_get_temp_dir()).DIRECTORY_SEPARATOR.'cmptest-'.md5(uniqid('', true));
+        $this->workingDir = $this->getUniqueTmpDirectory();
     }
 
     protected function tearDown()
@@ -317,7 +318,7 @@ class GitDownloaderTest extends \PHPUnit_Framework_TestCase
             ->method('execute')
             ->with($this->equalTo($expectedGitUpdateCommand))
             ->will($this->returnValue(1));
-        
+
         $this->fs->ensureDirectoryExists($this->workingDir.'/.git');
         $downloader = $this->getDownloaderMock(null, new Config(), $processExecutor);
         $downloader->update($packageMock, $packageMock, $this->workingDir);
diff --git a/tests/Composer/Test/Downloader/HgDownloaderTest.php b/tests/Composer/Test/Downloader/HgDownloaderTest.php
index b2dee627b..75dfa84aa 100644
--- a/tests/Composer/Test/Downloader/HgDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/HgDownloaderTest.php
@@ -13,16 +13,17 @@
 namespace Composer\Test\Downloader;
 
 use Composer\Downloader\HgDownloader;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 
-class HgDownloaderTest extends \PHPUnit_Framework_TestCase
+class HgDownloaderTest extends TestCase
 {
     /** @var string */
     private $workingDir;
 
     protected function setUp()
     {
-        $this->workingDir = realpath(sys_get_temp_dir()).DIRECTORY_SEPARATOR.'cmptest-'.md5(uniqid('', true));
+        $this->workingDir = $this->getUniqueTmpDirectory();
     }
 
     protected function tearDown()
diff --git a/tests/Composer/Test/Downloader/PearPackageExtractorTest.php b/tests/Composer/Test/Downloader/PearPackageExtractorTest.php
index 10ac27955..92004d0f1 100644
--- a/tests/Composer/Test/Downloader/PearPackageExtractorTest.php
+++ b/tests/Composer/Test/Downloader/PearPackageExtractorTest.php
@@ -13,8 +13,9 @@
 namespace Composer\Test\Downloader;
 
 use Composer\Downloader\PearPackageExtractor;
+use Composer\TestCase;
 
-class PearPackageExtractorTest extends \PHPUnit_Framework_TestCase
+class PearPackageExtractorTest extends TestCase
 {
     public function testShouldExtractPackage_1_0()
     {
@@ -122,7 +123,7 @@ class PearPackageExtractorTest extends \PHPUnit_Framework_TestCase
 
     public function testShouldPerformReplacements()
     {
-        $from = tempnam(sys_get_temp_dir(), 'pear-extract');
+        $from = tempnam($this->getUniqueTmpDirectory(), 'pear-extract');
         $to = $from.'-to';
 
         $original = 'replaced: @placeholder@; not replaced: @another@; replaced again: @placeholder@';
diff --git a/tests/Composer/Test/Downloader/PerforceDownloaderTest.php b/tests/Composer/Test/Downloader/PerforceDownloaderTest.php
index fc4297633..2b8105e65 100644
--- a/tests/Composer/Test/Downloader/PerforceDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/PerforceDownloaderTest.php
@@ -16,12 +16,13 @@ use Composer\Downloader\PerforceDownloader;
 use Composer\Config;
 use Composer\Repository\VcsRepository;
 use Composer\IO\IOInterface;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 
 /**
  * @author Matt Whittom <Matt.Whittom@veteransunited.com>
  */
-class PerforceDownloaderTest extends \PHPUnit_Framework_TestCase
+class PerforceDownloaderTest extends TestCase
 {
     protected $config;
     protected $downloader;
@@ -34,7 +35,7 @@ class PerforceDownloaderTest extends \PHPUnit_Framework_TestCase
 
     protected function setUp()
     {
-        $this->testPath        = sys_get_temp_dir() . '/composer-test';
+        $this->testPath        = $this->getUniqueTmpDirectory();
         $this->repoConfig      = $this->getRepoConfig();
         $this->config          = $this->getConfig();
         $this->io              = $this->getMockIoInterface();
diff --git a/tests/Composer/Test/Downloader/XzDownloaderTest.php b/tests/Composer/Test/Downloader/XzDownloaderTest.php
index a71516821..418776d75 100644
--- a/tests/Composer/Test/Downloader/XzDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/XzDownloaderTest.php
@@ -13,10 +13,11 @@
 namespace Composer\Test\Downloader;
 
 use Composer\Downloader\XzDownloader;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 use Composer\Util\RemoteFilesystem;
 
-class XzDownloaderTest extends \PHPUnit_Framework_TestCase
+class XzDownloaderTest extends TestCase
 {
     /**
      * @var Filesystem
@@ -33,7 +34,7 @@ class XzDownloaderTest extends \PHPUnit_Framework_TestCase
         if (defined('PHP_WINDOWS_VERSION_BUILD')) {
             $this->markTestSkipped('Skip test on Windows');
         }
-        $this->testDir = sys_get_temp_dir().'/composer-xz-test-vendor';
+        $this->testDir = $this->getUniqueTmpDirectory();
     }
 
     public function tearDown()
@@ -67,7 +68,7 @@ class XzDownloaderTest extends \PHPUnit_Framework_TestCase
         $downloader = new XzDownloader($io, $config, null, null, null, new RemoteFilesystem($io));
 
         try {
-            $downloader->download($packageMock, sys_get_temp_dir().'/composer-xz-test');
+            $downloader->download($packageMock, $this->getUniqueTmpDirectory());
             $this->fail('Download of invalid tarball should throw an exception');
         } catch (\RuntimeException $e) {
             $this->assertContains('File format not recognized', $e->getMessage());
diff --git a/tests/Composer/Test/Downloader/ZipDownloaderTest.php b/tests/Composer/Test/Downloader/ZipDownloaderTest.php
index 07a358fb9..a0507e730 100644
--- a/tests/Composer/Test/Downloader/ZipDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/ZipDownloaderTest.php
@@ -13,9 +13,10 @@
 namespace Composer\Test\Downloader;
 
 use Composer\Downloader\ZipDownloader;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 
-class ZipDownloaderTest extends \PHPUnit_Framework_TestCase
+class ZipDownloaderTest extends TestCase
 {
 
     /**
@@ -28,7 +29,8 @@ class ZipDownloaderTest extends \PHPUnit_Framework_TestCase
         if (!class_exists('ZipArchive')) {
             $this->markTestSkipped('zip extension missing');
         }
-        $this->testDir = sys_get_temp_dir().'/composer-zip-test-vendor';
+
+        $this->testDir = $this->getUniqueTmpDirectory();
     }
 
     public function tearDown()
diff --git a/tests/Composer/Test/Installer/LibraryInstallerTest.php b/tests/Composer/Test/Installer/LibraryInstallerTest.php
index 6230752e5..72eeb04b1 100644
--- a/tests/Composer/Test/Installer/LibraryInstallerTest.php
+++ b/tests/Composer/Test/Installer/LibraryInstallerTest.php
@@ -22,6 +22,7 @@ class LibraryInstallerTest extends TestCase
 {
     protected $composer;
     protected $config;
+    protected $rootDir;
     protected $vendorDir;
     protected $binDir;
     protected $dm;
@@ -37,10 +38,11 @@ class LibraryInstallerTest extends TestCase
         $this->config = new Config();
         $this->composer->setConfig($this->config);
 
-        $this->vendorDir = realpath(sys_get_temp_dir()).DIRECTORY_SEPARATOR.'composer-test-vendor';
+        $this->rootDir = $this->getUniqueTmpDirectory();
+        $this->vendorDir = $this->rootDir.DIRECTORY_SEPARATOR.'vendor';
         $this->ensureDirectoryExistsAndClear($this->vendorDir);
 
-        $this->binDir = realpath(sys_get_temp_dir()).DIRECTORY_SEPARATOR.'composer-test-bin';
+        $this->binDir = $this->rootDir.DIRECTORY_SEPARATOR.'bin';
         $this->ensureDirectoryExistsAndClear($this->binDir);
 
         $this->config->merge(array(
@@ -61,8 +63,7 @@ class LibraryInstallerTest extends TestCase
 
     protected function tearDown()
     {
-        $this->fs->removeDirectory($this->vendorDir);
-        $this->fs->removeDirectory($this->binDir);
+        $this->fs->removeDirectory($this->rootDir);
     }
 
     public function testInstallerCreationShouldNotCreateVendorDirectory()
diff --git a/tests/Composer/Test/Package/Archiver/ArchivableFilesFinderTest.php b/tests/Composer/Test/Package/Archiver/ArchivableFilesFinderTest.php
index f395eba6e..cce67c1aa 100644
--- a/tests/Composer/Test/Package/Archiver/ArchivableFilesFinderTest.php
+++ b/tests/Composer/Test/Package/Archiver/ArchivableFilesFinderTest.php
@@ -13,11 +13,12 @@
 namespace Composer\Test\Package\Archiver;
 
 use Composer\Package\Archiver\ArchivableFilesFinder;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 use Symfony\Component\Process\Process;
 use Symfony\Component\Process\ExecutableFinder;
 
-class ArchivableFilesFinderTest extends \PHPUnit_Framework_TestCase
+class ArchivableFilesFinderTest extends TestCase
 {
     protected $sources;
     protected $finder;
@@ -29,7 +30,7 @@ class ArchivableFilesFinderTest extends \PHPUnit_Framework_TestCase
         $this->fs = $fs;
 
         $this->sources = $fs->normalizePath(
-            realpath(sys_get_temp_dir()).'/composer_archiver_test'.uniqid(mt_rand(), true)
+            $this->getUniqueTmpDirectory()
         );
 
         $fileTree = array(
diff --git a/tests/Composer/Test/Package/Archiver/ArchiverTest.php b/tests/Composer/Test/Package/Archiver/ArchiverTest.php
index a3c73fa7a..32a6ed749 100644
--- a/tests/Composer/Test/Package/Archiver/ArchiverTest.php
+++ b/tests/Composer/Test/Package/Archiver/ArchiverTest.php
@@ -12,11 +12,12 @@
 
 namespace Composer\Test\Package\Archiver;
 
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 use Composer\Util\ProcessExecutor;
 use Composer\Package\Package;
 
-abstract class ArchiverTest extends \PHPUnit_Framework_TestCase
+abstract class ArchiverTest extends TestCase
 {
     /**
      * @var \Composer\Util\Filesystem
@@ -37,8 +38,7 @@ abstract class ArchiverTest extends \PHPUnit_Framework_TestCase
     {
         $this->filesystem = new Filesystem();
         $this->process    = new ProcessExecutor();
-        $this->testDir    = sys_get_temp_dir().'/composer_archiver_test_'.mt_rand();
-        $this->filesystem->ensureDirectoryExists($this->testDir);
+        $this->testDir    = $this->getUniqueTmpDirectory();
     }
 
     public function tearDown()
diff --git a/tests/Composer/Test/Package/Archiver/PharArchiverTest.php b/tests/Composer/Test/Package/Archiver/PharArchiverTest.php
index d6e783c91..16753784d 100644
--- a/tests/Composer/Test/Package/Archiver/PharArchiverTest.php
+++ b/tests/Composer/Test/Package/Archiver/PharArchiverTest.php
@@ -21,14 +21,14 @@ class PharArchiverTest extends ArchiverTest
         // Set up repository
         $this->setupDummyRepo();
         $package = $this->setupPackage();
-        $target  = sys_get_temp_dir().'/composer_archiver_test.tar';
+        $target  = $this->getUniqueTmpDirectory().'/composer_archiver_test.tar';
 
         // Test archive
         $archiver = new PharArchiver();
         $archiver->archive($package->getSourceUrl(), $target, 'tar', array('foo/bar', 'baz', '!/foo/bar/baz'));
         $this->assertFileExists($target);
 
-        unlink($target);
+        $this->filesystem->removeDirectory(dirname($target));
     }
 
     public function testZipArchive()
@@ -36,14 +36,14 @@ class PharArchiverTest extends ArchiverTest
         // Set up repository
         $this->setupDummyRepo();
         $package = $this->setupPackage();
-        $target  = sys_get_temp_dir().'/composer_archiver_test.zip';
+        $target  = $this->getUniqueTmpDirectory().'/composer_archiver_test.zip';
 
         // Test archive
         $archiver = new PharArchiver();
         $archiver->archive($package->getSourceUrl(), $target, 'zip');
         $this->assertFileExists($target);
 
-        unlink($target);
+        $this->filesystem->removeDirectory(dirname($target));
     }
 
     /**
diff --git a/tests/Composer/Test/Plugin/PluginInstallerTest.php b/tests/Composer/Test/Plugin/PluginInstallerTest.php
index c26965d33..8d3a5e4dc 100644
--- a/tests/Composer/Test/Plugin/PluginInstallerTest.php
+++ b/tests/Composer/Test/Plugin/PluginInstallerTest.php
@@ -69,7 +69,7 @@ class PluginInstallerTest extends TestCase
     {
         $loader = new JsonLoader(new ArrayLoader());
         $this->packages = array();
-        $this->directory = sys_get_temp_dir() . '/' . uniqid();
+        $this->directory = $this->getUniqueTmpDirectory();
         for ($i = 1; $i <= 7; $i++) {
             $filename = '/Fixtures/plugin-v'.$i.'/composer.json';
             mkdir(dirname($this->directory . $filename), 0777, true);
diff --git a/tests/Composer/Test/Repository/FilesystemRepositoryTest.php b/tests/Composer/Test/Repository/FilesystemRepositoryTest.php
index 6f8b71d20..cde5eb402 100644
--- a/tests/Composer/Test/Repository/FilesystemRepositoryTest.php
+++ b/tests/Composer/Test/Repository/FilesystemRepositoryTest.php
@@ -42,7 +42,7 @@ class FilesystemRepositoryTest extends TestCase
     }
 
     /**
-     * @expectedException Composer\Repository\InvalidRepositoryException
+     * @expectedException \Composer\Repository\InvalidRepositoryException
      */
     public function testCorruptedRepositoryFile()
     {
diff --git a/tests/Composer/Test/Repository/Vcs/GitHubDriverTest.php b/tests/Composer/Test/Repository/Vcs/GitHubDriverTest.php
index cd40a71f2..ee7ad38fd 100644
--- a/tests/Composer/Test/Repository/Vcs/GitHubDriverTest.php
+++ b/tests/Composer/Test/Repository/Vcs/GitHubDriverTest.php
@@ -14,19 +14,22 @@ namespace Composer\Test\Repository\Vcs;
 
 use Composer\Downloader\TransportException;
 use Composer\Repository\Vcs\GitHubDriver;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 use Composer\Config;
 
-class GitHubDriverTest extends \PHPUnit_Framework_TestCase
+class GitHubDriverTest extends TestCase
 {
+    private $home;
     private $config;
 
     public function setUp()
     {
+        $this->home = $this->getUniqueTmpDirectory();
         $this->config = new Config();
         $this->config->merge(array(
             'config' => array(
-                'home' => sys_get_temp_dir() . '/composer-test',
+                'home' => $this->home,
             ),
         ));
     }
@@ -34,7 +37,7 @@ class GitHubDriverTest extends \PHPUnit_Framework_TestCase
     public function tearDown()
     {
         $fs = new Filesystem;
-        $fs->removeDirectory(sys_get_temp_dir() . '/composer-test');
+        $fs->removeDirectory($this->home);
     }
 
     public function testPrivateRepository()
diff --git a/tests/Composer/Test/Repository/Vcs/GitLabDriverTest.php b/tests/Composer/Test/Repository/Vcs/GitLabDriverTest.php
index dc08b9aa8..e1ac82021 100644
--- a/tests/Composer/Test/Repository/Vcs/GitLabDriverTest.php
+++ b/tests/Composer/Test/Repository/Vcs/GitLabDriverTest.php
@@ -14,29 +14,42 @@ namespace Composer\Test\Repository\Vcs;
 
 use Composer\Repository\Vcs\GitLabDriver;
 use Composer\Config;
+use Composer\TestCase;
+use Composer\Util\Filesystem;
 
 /**
  * @author Jérôme Tamarelle <jerome@tamarelle.net>
  */
-class GitLabDriverTest extends \PHPUnit_Framework_TestCase
+class GitLabDriverTest extends TestCase
 {
+    private $home;
+    private $config;
+    private $io;
+    private $process;
+    private $remoteFilesystem;
+
     public function setUp()
     {
+        $this->home = $this->getUniqueTmpDirectory();
         $this->config = new Config();
         $this->config->merge(array(
             'config' => array(
-                'home' => sys_get_temp_dir().'/composer-test',
+                'home' => $this->home,
                 'gitlab-domains' => array('mycompany.com/gitlab', 'gitlab.com')
             ),
         ));
 
         $this->io = $this->prophesize('Composer\IO\IOInterface');
-
         $this->process = $this->prophesize('Composer\Util\ProcessExecutor');
-
         $this->remoteFilesystem = $this->prophesize('Composer\Util\RemoteFilesystem');
     }
 
+    public function tearDown()
+    {
+        $fs = new Filesystem();
+        $fs->removeDirectory($this->home);
+    }
+
     public function getInitializeUrls()
     {
         return array(
diff --git a/tests/Composer/Test/Repository/Vcs/PerforceDriverTest.php b/tests/Composer/Test/Repository/Vcs/PerforceDriverTest.php
index 59030f506..987751408 100644
--- a/tests/Composer/Test/Repository/Vcs/PerforceDriverTest.php
+++ b/tests/Composer/Test/Repository/Vcs/PerforceDriverTest.php
@@ -13,6 +13,7 @@
 namespace Composer\Test\Repository\Vcs;
 
 use Composer\Repository\Vcs\PerforceDriver;
+use Composer\TestCase;
 use Composer\Util\Filesystem;
 use Composer\Config;
 use Composer\Util\Perforce;
@@ -20,7 +21,7 @@ use Composer\Util\Perforce;
 /**
  * @author Matt Whittom <Matt.Whittom@veteransunited.com>
  */
-class PerforceDriverTest extends \PHPUnit_Framework_TestCase
+class PerforceDriverTest extends TestCase
 {
     protected $config;
     protected $io;
@@ -29,6 +30,7 @@ class PerforceDriverTest extends \PHPUnit_Framework_TestCase
     protected $testPath;
     protected $driver;
     protected $repoConfig;
+    protected $perforce;
 
     const TEST_URL    = 'TEST_PERFORCE_URL';
     const TEST_DEPOT  = 'TEST_DEPOT_CONFIG';
@@ -36,7 +38,7 @@ class PerforceDriverTest extends \PHPUnit_Framework_TestCase
 
     protected function setUp()
     {
-        $this->testPath         = sys_get_temp_dir() . '/composer-test';
+        $this->testPath         = $this->getUniqueTmpDirectory();
         $this->config           = $this->getTestConfig($this->testPath);
         $this->repoConfig       = $this->getTestRepoConfig();
         $this->io               = $this->getMockIOInterface();
diff --git a/tests/Composer/Test/Repository/Vcs/SvnDriverTest.php b/tests/Composer/Test/Repository/Vcs/SvnDriverTest.php
index 2ef1baa18..c2ae497ca 100644
--- a/tests/Composer/Test/Repository/Vcs/SvnDriverTest.php
+++ b/tests/Composer/Test/Repository/Vcs/SvnDriverTest.php
@@ -14,9 +14,31 @@ namespace Composer\Test\Repository\Vcs;
 
 use Composer\Repository\Vcs\SvnDriver;
 use Composer\Config;
+use Composer\TestCase;
+use Composer\Util\Filesystem;
 
-class SvnDriverTest extends \PHPUnit_Framework_TestCase
+class SvnDriverTest extends TestCase
 {
+    protected $home;
+    protected $config;
+
+    public function setUp()
+    {
+        $this->home = $this->getUniqueTmpDirectory();
+        $this->config = new Config();
+        $this->config->merge(array(
+            'config' => array(
+                'home' => $this->home,
+            ),
+        ));
+    }
+
+    public function tearDown()
+    {
+        $fs = new Filesystem();
+        $fs->removeDirectory($this->home);
+    }
+
     /**
      * @expectedException RuntimeException
      */
@@ -39,17 +61,11 @@ class SvnDriverTest extends \PHPUnit_Framework_TestCase
             ->method('execute')
             ->will($this->returnValue(0));
 
-        $config = new Config();
-        $config->merge(array(
-            'config' => array(
-                'home' => sys_get_temp_dir() . '/composer-test',
-            ),
-        ));
         $repoConfig = array(
             'url' => 'http://till:secret@corp.svn.local/repo',
         );
 
-        $svn = new SvnDriver($repoConfig, $console, $config, $process);
+        $svn = new SvnDriver($repoConfig, $console, $this->config, $process);
         $svn->initialize();
     }
 
diff --git a/tests/Composer/Test/Repository/VcsRepositoryTest.php b/tests/Composer/Test/Repository/VcsRepositoryTest.php
index eaedc82a9..61e29be37 100644
--- a/tests/Composer/Test/Repository/VcsRepositoryTest.php
+++ b/tests/Composer/Test/Repository/VcsRepositoryTest.php
@@ -12,6 +12,7 @@
 
 namespace Composer\Test\Repository;
 
+use Composer\TestCase;
 use Symfony\Component\Process\ExecutableFinder;
 use Composer\Package\Dumper\ArrayDumper;
 use Composer\Repository\VcsRepository;
@@ -23,7 +24,7 @@ use Composer\Config;
 /**
  * @group slow
  */
-class VcsRepositoryTest extends \PHPUnit_Framework_TestCase
+class VcsRepositoryTest extends TestCase
 {
     private static $composerHome;
     private static $gitRepo;
@@ -32,8 +33,8 @@ class VcsRepositoryTest extends \PHPUnit_Framework_TestCase
     protected function initialize()
     {
         $oldCwd = getcwd();
-        self::$composerHome = sys_get_temp_dir() . '/composer-home-'.mt_rand().'/';
-        self::$gitRepo = sys_get_temp_dir() . '/composer-git-'.mt_rand().'/';
+        self::$composerHome = $this->getUniqueTmpDirectory();
+        self::$gitRepo = $this->getUniqueTmpDirectory();
 
         $locator = new ExecutableFinder();
         if (!$locator->find('git')) {
diff --git a/tests/Composer/Test/Util/FilesystemTest.php b/tests/Composer/Test/Util/FilesystemTest.php
index d7c986369..969572036 100644
--- a/tests/Composer/Test/Util/FilesystemTest.php
+++ b/tests/Composer/Test/Util/FilesystemTest.php
@@ -44,8 +44,8 @@ class FilesystemTest extends TestCase
     public function setUp()
     {
         $this->fs = new Filesystem;
-        $this->workingDir = sys_get_temp_dir() . '/composer_testdir';
-        $this->testFile = sys_get_temp_dir() . '/composer_test_file';
+        $this->workingDir = $this->getUniqueTmpDirectory();
+        $this->testFile = $this->getUniqueTmpDirectory() . '/composer_test_file';
     }
 
     public function tearDown()
@@ -54,7 +54,7 @@ class FilesystemTest extends TestCase
             $this->fs->removeDirectory($this->workingDir);
         }
         if (is_file($this->testFile)) {
-            $this->fs->remove($this->testFile);
+            $this->fs->removeDirectory(dirname($this->testFile));
         }
     }
 
diff --git a/tests/Composer/TestCase.php b/tests/Composer/TestCase.php
index 2057c09b8..a065f200c 100644
--- a/tests/Composer/TestCase.php
+++ b/tests/Composer/TestCase.php
@@ -56,12 +56,29 @@ abstract class TestCase extends \PHPUnit_Framework_TestCase
         return new AliasPackage($package, $normVersion, $version);
     }
 
-    protected function ensureDirectoryExistsAndClear($directory)
+    protected static function getUniqueTmpDirectory()
+    {
+        $attempts = 5;
+        $root = sys_get_temp_dir();
+
+        do {
+            $unique = $root . DIRECTORY_SEPARATOR . uniqid('composer-test-');
+            if (!file_exists($unique) && mkdir($unique, 0777)) {
+                return realpath($unique);
+            }
+        } while (--$attempts);
+
+        throw new \RuntimeException('Failed to create a unique temporary directory.');
+    }
+
+    protected static function ensureDirectoryExistsAndClear($directory)
     {
         $fs = new Filesystem();
+
         if (is_dir($directory)) {
             $fs->removeDirectory($directory);
         }
+
         mkdir($directory, 0777, true);
     }
 }