diff --git a/tests/unit/framework/db/DatabaseTestCase.php b/tests/unit/framework/db/DatabaseTestCase.php
index 54316c7..8ef1234 100644
--- a/tests/unit/framework/db/DatabaseTestCase.php
+++ b/tests/unit/framework/db/DatabaseTestCase.php
@@ -12,7 +12,6 @@ abstract class DatabaseTestCase extends TestCase
 	 * @var Connection
 	 */
 	protected $db;
-	protected $initializeAppWithDb = false;
 
 	protected function setUp()
 	{
@@ -24,9 +23,6 @@ abstract class DatabaseTestCase extends TestCase
 		if (!extension_loaded('pdo') || !extension_loaded($pdo_database)) {
 			$this->markTestSkipped('pdo and '.$pdo_database.' extension are required.');
 		}
-		if ($this->initializeAppWithDb === true) {
-			\Yii::$app->setComponent('db', $this->getConnection());
-		}
 		$this->mockApplication();
 	}
 
diff --git a/tests/unit/framework/validators/ExistValidatorTest.php b/tests/unit/framework/validators/ExistValidatorTest.php
index 40d0935..ea81931 100644
--- a/tests/unit/framework/validators/ExistValidatorTest.php
+++ b/tests/unit/framework/validators/ExistValidatorTest.php
@@ -19,12 +19,7 @@ class ExistValidatorTest extends DatabaseTestCase
 	public function setUp()
 	{
 		parent::setUp();
-		ActiveRecord::$db = Yii::$app->getComponent('db');
-	}
-
-	public function tearDown()
-	{
-		parent::tearDown();
+		ActiveRecord::$db = $this->getConnection();
 	}
 
 	public function testValidateValueExpectedException()
diff --git a/tests/unit/framework/validators/UniqueValidatorTest.php b/tests/unit/framework/validators/UniqueValidatorTest.php
index b0d3554..1142fe0 100644
--- a/tests/unit/framework/validators/UniqueValidatorTest.php
+++ b/tests/unit/framework/validators/UniqueValidatorTest.php
@@ -20,7 +20,7 @@ class UniqueValidatorTest extends DatabaseTestCase
 	public function setUp()
 	{
 		parent::setUp();
-		ActiveRecord::$db = Yii::$app->getComponent('db');
+		ActiveRecord::$db = $this->getConnection();
 	}
 
 	public function testAssureMessageSetOnInit()