diff -u b/tests/libraries.drush.test b/tests/libraries.drush.test
--- b/tests/libraries.drush.test
+++ b/tests/libraries.drush.test
@@ -6,99 +6,100 @@
 
-/**
- * Class LibrariesDrushTestCase.
- */
-class LibrariesDrushTestCase extends DrupalWebTestCase {
-
-  const TEST_MODULE = 'libraries_test_download';
-  /**
-   * @var LibrariesManager
-   */
-  private $manager;
-  /**
-   * @var string[]
-   */
-  private $libraries = array();
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function getInfo() {
-    return array(
-      'name' => 'Drush integration',
-      'group' => 'Libraries API',
-      'description' => 'Testing Drush integration.',
-    );
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function setUp() {
-    $this->profile = drupal_get_profile();
+// Allow to run these tests only by Drush. Otherwise they are will not work
+// because SimpleTest renames database connection and Drush cannot use it.
+// Also, Drush functionality has been used.
+if (function_exists('drush_mkdir')) {
+  /**
+   * Class LibrariesDrushTestCase.
+   */
+  class LibrariesDrushTestCase extends DrupalWebTestCase {
+
+    const TEST_MODULE = 'libraries_test_download';
+    /**
+     * @var LibrariesManager
+     */
+    private $manager;
+    /**
+     * @var string[]
+     */
+    private $libraries = array();
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getInfo() {
+      return array(
+        'name' => 'Drush integration',
+        'group' => 'Libraries API',
+        'description' => 'Testing Drush integration.',
+      );
+    }
 
-    parent::setUp(self::TEST_MODULE);
+    /**
+     * {@inheritdoc}
+     */
+    public function setUp() {
+      $this->profile = drupal_get_profile();
 
-    // Allow to run these tests only by Drush. Otherwise they are will not work
-    // because SimpleTest renames database connection and Drush cannot use it.
-    // Also, Drush functionality has been used.
-    $this->setup = function_exists('drush_mkdir');
-    $this->manager = new LibrariesManager();
-    $this->libraries = array_keys(module_invoke(self::TEST_MODULE, 'libraries_info'));
-  }
+      parent::setUp(self::TEST_MODULE);
 
-  /**
-   * {@inheritdoc}
-   */
-  public function tearDown() {
-    parent::tearDown();
-    $this->manager->uninstall(self::TEST_MODULE);
-  }
-
-  /**
-   * Testing manual downloading.
-   *
-   * @param array $options
-   *   Options for "libget" command.
-   */
-  public function testManualDownloading(array $options = array()) {
-    foreach ($this->libraries as $library) {
-      $info = libraries_detect($library);
-      $this->assertFalse($info['installed']);
-
-      $this->manager->download(array($library), $options);
-      drupal_flush_all_caches();
+      $this->manager = new LibrariesManager();
+      $this->libraries = array_keys(module_invoke(self::TEST_MODULE, 'libraries_info'));
+    }
 
-      $info = libraries_detect($library);
-      $this->assertTrue($info['installed']);
+    /**
+     * {@inheritdoc}
+     */
+    public function tearDown() {
+      parent::tearDown();
+      $this->manager->uninstall(self::TEST_MODULE);
     }
-  }
 
-  /**
-   * Testing manual downloading to sub-site.
-   *
-   * @param string $site
-   *   Sub-site machine name.
-   */
-  public function testDownloadingToSubSite($site = 'testing') {
-    $path = "sites/$site";
+    /**
+     * Testing manual downloading.
+     *
+     * @param array $options
+     *   Options for "libget" command.
+     */
+    public function testManualDownloading(array $options = array()) {
+      foreach ($this->libraries as $library) {
+        $info = libraries_detect($library);
+        $this->assertFalse($info['installed']);
+
+        $this->manager->download(array($library), $options);
+        drupal_flush_all_caches();
+
+        $info = libraries_detect($library);
+        $this->assertTrue($info['installed']);
+      }
+    }
 
-    $this->assertTrue(drush_mkdir($path));
-    $this->assertTrue(file_unmanaged_copy('sites/default/settings.php', $path));
+    /**
+     * Testing manual downloading to sub-site.
+     *
+     * @param string $site
+     *   Sub-site machine name.
+     */
+    public function testDownloadingToSubSite($site = 'testing') {
+      $path = "sites/$site";
+
+      $this->assertTrue(drush_mkdir($path));
+      $this->assertTrue(file_unmanaged_copy('sites/default/settings.php', $path));
+
+      // @see conf_path()
+      // @see libraries_get_libraries()
+      $conf =& drupal_static('conf_path');
+      $conf = $path;
 
-    // @see conf_path()
-    // @see libraries_get_libraries()
-    $conf =& drupal_static('conf_path');
-    $conf = $path;
+      $this->testManualDownloading(array('uri' => $site));
+      $this->assertTrue(drush_delete_dir($path));
+    }
 
-    $this->testManualDownloading(array('uri' => $site));
-    $this->assertTrue(drush_delete_dir($path));
-  }
+    /**
+     * Testing manual downloading to profile.
+     */
+    public function testDownloadingToProfile() {
+      $this->testManualDownloading(array('profile' => TRUE));
+    }
 
-  /**
-   * Testing manual downloading to profile.
-   */
-  public function testDownloadingToProfile() {
-    $this->testManualDownloading(array('profile' => TRUE));
   }
-
 }