diff --git a/tests/unit/VendorTestCase.php b/tests/unit/VendorTestCase.php
index 2002cb3..71a2648 100644
--- a/tests/unit/VendorTestCase.php
+++ b/tests/unit/VendorTestCase.php
@@ -27,4 +27,4 @@ class VendorTestCase extends TestCase
 			throw new NotSupportedException("Vendor autoload file '{$vendorAutoload}' is missing.");
 		}
 	}
-}
\ No newline at end of file
+}
diff --git a/tests/unit/extensions/swiftmailer/MessageTest.php b/tests/unit/extensions/swiftmailer/MessageTest.php
index 1f55cc6..31a5c43 100644
--- a/tests/unit/extensions/swiftmailer/MessageTest.php
+++ b/tests/unit/extensions/swiftmailer/MessageTest.php
@@ -56,7 +56,9 @@ class MessageTest extends VendorTestCase
 	 */
 	protected function createTestEmailComponent()
 	{
-		$component = new Mailer();
+		$component = new Mailer([
+			'useFileTransport' => true,
+		]);
 		return $component;
 	}