diff --git a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
index 5725ed8..77c0b4d 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -86,6 +86,10 @@ abstract class TestBase {
    */
   protected $setup = FALSE;
 
+  protected $setupDatabasePrefix = FALSE;
+
+  protected $setupEnvironment = FALSE;
+
   /**
    * Constructor for Test.
    *
@@ -593,6 +597,8 @@ abstract class TestBase {
       );
     }
     Database::addConnectionInfo('default', 'default', $connection_info['default']);
+
+    $this->setupDatabasePrefix = TRUE;
   }
 
   /**
@@ -661,6 +667,8 @@ abstract class TestBase {
     $test_info = &$GLOBALS['drupal_test_info'];
     $test_info['test_run_id'] = $this->databasePrefix;
     $test_info['in_child_site'] = FALSE;
+
+    $this->setupEnvironment = TRUE;
   }
 
   /**
@@ -687,9 +695,15 @@ abstract class TestBase {
     }
 
     // Delete temporary files directory.
+    if (!$this->setupEnvironment) {
+      return FALSE;
+    }
     file_unmanaged_delete_recursive($this->originalFileDirectory . '/simpletest/' . substr($this->databasePrefix, 10));
 
     // Restore original database connection.
+    if (!$this->setupDatabasePrefix) {
+      return FALSE;
+    }
     Database::removeConnection('default');
     Database::renameConnection('simpletest_original_default', 'default');
 
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
index a871639..d54912a 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/UnitTestBase.php
@@ -43,6 +43,9 @@ abstract class UnitTestBase extends TestBase {
 
     // Prepare the environment for running tests.
     $this->prepareEnvironment();
+    if (!$this->setupEnvironment) {
+      return FALSE;
+    }
     $this->originalThemeRegistry = theme_get_registry(FALSE);
 
     // Reset all statics and variables to perform tests in a clean environment.
@@ -65,6 +68,9 @@ abstract class UnitTestBase extends TestBase {
     // changed, since Drupal\Core\Utility\CacheArray implementations attempt to
     // write back to persistent caches when they are destructed.
     $this->changeDatabasePrefix();
+    if (!$this->setupDatabasePrefix) {
+      return FALSE;
+    }
 
     // Set user agent to be consistent with WebTestBase.
     $_SERVER['HTTP_USER_AGENT'] = $this->databasePrefix;
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index 0856611..b74a00c 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -586,6 +586,9 @@ abstract class WebTestBase extends TestBase {
 
     // Prepare the environment for running tests.
     $this->prepareEnvironment();
+    if (!$this->setupEnvironment) {
+      return FALSE;
+    }
 
     // Reset all statics and variables to perform tests in a clean environment.
     $conf = array();
@@ -596,6 +599,9 @@ abstract class WebTestBase extends TestBase {
     // changed, since Drupal\Core\Utility\CacheArray implementations attempt to
     // write back to persistent caches when they are destructed.
     $this->changeDatabasePrefix();
+    if (!$this->setupDatabasePrefix) {
+      return FALSE;
+    }
 
     // Preset the 'install_profile' system variable, so the first call into
     // system_rebuild_module_data() (in drupal_install_system()) will register
@@ -754,6 +760,9 @@ abstract class WebTestBase extends TestBase {
    */
   protected function tearDown() {
     // Remove all prefixed tables.
+    if (!$this->setupDatabasePrefix) {
+      return FALSE;
+    }
     $connection_info = Database::getConnectionInfo('default');
     $tables = db_find_tables($connection_info['default']['prefix']['default'] . '%');
     if (empty($tables)) {