diff --git a/app/tests/Controller/User/RegisterUserActionTest.php b/app/tests/Controller/User/RegisterUserActionTest.php
index cafd73b..95f73c8 100644
--- a/app/tests/Controller/User/RegisterUserActionTest.php
+++ b/app/tests/Controller/User/RegisterUserActionTest.php
@@ -92,11 +92,19 @@ class RegisterUserActionTest extends TestCase
         $response = $app->handle($request);
         $this->assertEquals(400, $response->getStatusCode());
 
+        $responseBody = $response->getBody();
+        $this->assertTrue((bool)preg_match('/flash error/', $responseBody));
+        $this->assertTrue((bool)preg_match('/Unable to register user/', $responseBody));
+
+        /**
+         * The Flash messages are already exhausted while rendering the
+         * templates. We should check the template for the error.
+         */
         $flash = $container->get(SessionInterface::class)->getFlash();
         $errorMessages = $flash->get('error');
         $this->assertIsArray($errorMessages);
-        $this->assertNotEmpty($errorMessages);
-        $this->assertEquals('Unable to register user.', $errorMessages[0]);
+        //$this->assertNotEmpty($errorMessages);
+        //$this->assertEquals('Unable to register user.', $errorMessages[0]);
     }
 
     public function testMismatchPassword(): void