diff --git a/tests/unit/extensions/swiftmailer/MailerTest.php b/tests/unit/extensions/swiftmailer/MailerTest.php
index dbc93f3..ce88711 100644
--- a/tests/unit/extensions/swiftmailer/MailerTest.php
+++ b/tests/unit/extensions/swiftmailer/MailerTest.php
@@ -4,9 +4,10 @@ namespace yiiunit\extensions\swiftmailer;
 
 use Yii;
 use yii\swiftmailer\Mailer;
-use yii\swiftmailer\Message;
 use yiiunit\VendorTestCase;
 
+Yii::setAlias('@yii/swiftmailer', __DIR__ . '/../../../../extensions/swiftmailer');
+
 /**
  * @group vendor
  * @group mail
diff --git a/tests/unit/extensions/swiftmailer/MessageTest.php b/tests/unit/extensions/swiftmailer/MessageTest.php
index 6309f15..1f55cc6 100644
--- a/tests/unit/extensions/swiftmailer/MessageTest.php
+++ b/tests/unit/extensions/swiftmailer/MessageTest.php
@@ -8,6 +8,8 @@ use yii\swiftmailer\Mailer;
 use yii\swiftmailer\Message;
 use yiiunit\VendorTestCase;
 
+Yii::setAlias('@yii/swiftmailer', __DIR__ . '/../../../../extensions/swiftmailer');
+
 /**
  * @group vendor
  * @group mail