diff --git a/tests/integration/controller/RegisterControllerTest.php b/tests/integration/controller/RegisterControllerTest.php
index 042fb95..c5290bf 100644
--- a/tests/integration/controller/RegisterControllerTest.php
+++ b/tests/integration/controller/RegisterControllerTest.php
@@ -126,7 +126,7 @@ class RegistrationControllerTest extends TestCase {
 			->method('getAppValue')
 			->with("registration", 'allowed_domains', '')
 			->willReturn('');
-		$this->mailService->expects($this->at(0))
+		$this->mailService->expects($this->once())
 			->method('sendTokenByMail')
 			->willReturn(true);