diff --git a/core/modules/migrate/lib/Drupal/migrate/Tests/MigrateTestBase.php b/core/modules/migrate/lib/Drupal/migrate/Tests/MigrateTestBase.php
index 9a4b5bd..512441f 100644
--- a/core/modules/migrate/lib/Drupal/migrate/Tests/MigrateTestBase.php
+++ b/core/modules/migrate/lib/Drupal/migrate/Tests/MigrateTestBase.php
@@ -11,9 +11,9 @@
 use Drupal\migrate\Entity\MigrationInterface;
 use Drupal\migrate\MigrateMessageInterface;
 use Drupal\migrate\Row;
-use Drupal\simpletest\WebTestBase;
+use Drupal\simpletest\DrupalUnitTestBase;
 
-class MigrateTestBase extends WebTestBase implements MigrateMessageInterface {
+class MigrateTestBase extends DrupalUnitTestBase implements MigrateMessageInterface {
 
   /**
    * The file path(s) to the dumped database(s) to load into the child site.
@@ -49,11 +49,10 @@ protected function setUp() {
     parent::setUp();
     $connection_info = Database::getConnectionInfo('default');
     foreach ($connection_info as $target => $value) {
-      $connection_info[$target]['prefix'] = array(
-        // Simpletest uses 7 character prefixes at most so this can't cause
-        // collisions.
-        'default' => $value['prefix']['default'] . '0',
-      );
+      $prefix = is_array($value['prefix']) ? $value['prefix']['default'] : $value['prefix'];
+      // Simpletest uses 7 character prefixes at most so this can't cause
+      // collisions.
+      $connection_info[$target]['prefix'] = $prefix . '0';
     }
     Database::addConnectionInfo('migrate', 'default', $connection_info['default']);
   }
diff --git a/core/modules/migrate_drupal/lib/Drupal/migrate_drupal/Tests/MigrateDrupalTestBase.php b/core/modules/migrate_drupal/lib/Drupal/migrate_drupal/Tests/MigrateDrupalTestBase.php
index f660102..b864501 100644
--- a/core/modules/migrate_drupal/lib/Drupal/migrate_drupal/Tests/MigrateDrupalTestBase.php
+++ b/core/modules/migrate_drupal/lib/Drupal/migrate_drupal/Tests/MigrateDrupalTestBase.php
@@ -18,6 +18,11 @@ class MigrateDrupalTestBase extends MigrateTestBase {
    */
   public static $modules = array('migrate_drupal');
 
+  protected function setUp() {
+    parent::setUp();
+    $this->installConfig(array('migrate_drupal'));
+  }
+
   /**
    * Returns the path to the dump directory.
    *