diff --git a/src/Test/TestUtil.php b/src/Test/TestUtil.php
new file mode 100644
index 0000000..841d27a
--- /dev/null
+++ b/src/Test/TestUtil.php
@@ -0,0 +1,56 @@
+<?php
+
+/*
+ * This file is part of the webmozart/glob package.
+ *
+ * (c) Bernhard Schussek <bschussek@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Webmozart\Glob\Test;
+
+/**
+ * Contains utility methods for testing.
+ *
+ * @since  3.1
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ */
+final class TestUtil
+{
+    /**
+     * Creates a temporary directory.
+     *
+     * @param string $namespace The directory path in the system's temporary
+     *                          directory.
+     * @param string $className The name of the test class.
+     *
+     * @return string The path to the created directory.
+     */
+    public static function makeTempDir($namespace, $className)
+    {
+        if (false !== ($pos = strrpos($className, '\\'))) {
+            $shortClass = substr($className, $pos + 1);
+        } else {
+            $shortClass = $className;
+        }
+
+        // Usage of realpath() is important if the temporary directory is a
+        // symlink to another directory (e.g. /var => /private/var on some Macs)
+        // We want to know the real path to avoid comparison failures with
+        // code that uses real paths only
+        $basePath = realpath(sys_get_temp_dir()).'/'.$namespace.'/'.$shortClass;
+
+        while (false === @mkdir($tempDir = $basePath.rand(10000, 99999), 0777, true)) {
+            // Run until we are able to create a directory
+        }
+
+        return $tempDir;
+    }
+
+    private function __construct()
+    {
+    }
+}
diff --git a/tests/GlobTest.php b/tests/GlobTest.php
index 173ece2..349f1c8 100644
--- a/tests/GlobTest.php
+++ b/tests/GlobTest.php
@@ -14,6 +14,7 @@
 use PHPUnit_Framework_TestCase;
 use Symfony\Component\Filesystem\Filesystem;
 use Webmozart\Glob\Glob;
+use Webmozart\Glob\Test\TestUtil;
 
 /**
  * @since  1.0
@@ -26,8 +27,7 @@ class GlobTest extends PHPUnit_Framework_TestCase
 
     protected function setUp()
     {
-        while (false === @mkdir($this->tempDir = sys_get_temp_dir().'/webmozart-glob/GlobTest'.rand(10000, 99999), 0777, true)) {
-        }
+        $this->tempDir = TestUtil::makeTempDir('webmozart-glob', __CLASS__);
 
         $filesystem = new Filesystem();
         $filesystem->mirror(__DIR__.'/Fixtures', $this->tempDir);
diff --git a/tests/Iterator/GlobIteratorTest.php b/tests/Iterator/GlobIteratorTest.php
index 303c3e1..a7580a2 100644
--- a/tests/Iterator/GlobIteratorTest.php
+++ b/tests/Iterator/GlobIteratorTest.php
@@ -15,6 +15,7 @@
 use Symfony\Component\Filesystem\Filesystem;
 use Webmozart\Glob\Glob;
 use Webmozart\Glob\Iterator\GlobIterator;
+use Webmozart\Glob\Test\TestUtil;
 
 /**
  * @since  1.0
@@ -29,8 +30,7 @@ class GlobIteratorTest extends PHPUnit_Framework_TestCase
 
     protected function setUp()
     {
-        while (false === @mkdir($this->tempDir = sys_get_temp_dir().'/webmozart-glob/GlobIteratorTest'.rand(10000, 99999), 0777, true)) {
-        }
+        $this->tempDir = TestUtil::makeTempDir('webmozart-glob', __CLASS__);
 
         $filesystem = new Filesystem();
         $filesystem->mirror(__DIR__.'/../Fixtures', $this->tempDir);
diff --git a/tests/Iterator/RecursiveDirectoryIteratorTest.php b/tests/Iterator/RecursiveDirectoryIteratorTest.php
index 3c2470b..022c976 100644
--- a/tests/Iterator/RecursiveDirectoryIteratorTest.php
+++ b/tests/Iterator/RecursiveDirectoryIteratorTest.php
@@ -15,6 +15,7 @@
 use RecursiveIteratorIterator;
 use Symfony\Component\Filesystem\Filesystem;
 use Webmozart\Glob\Iterator\RecursiveDirectoryIterator;
+use Webmozart\Glob\Test\TestUtil;
 
 /**
  * @since  1.0
@@ -27,8 +28,7 @@ class RecursiveDirectoryIteratorTest extends PHPUnit_Framework_TestCase
 
     protected function setUp()
     {
-        while (false === mkdir($this->tempDir = sys_get_temp_dir().'/webmozart-glob/RecursiveDirectoryIteratorTest'.rand(10000, 99999), 0777, true)) {
-        }
+        $this->tempDir = TestUtil::makeTempDir('webmozart-glob', __CLASS__);
 
         $filesystem = new Filesystem();
         $filesystem->mirror(__DIR__.'/../Fixtures', $this->tempDir);