diff --git a/src/Testing/InteractsWithMail.php b/src/Testing/InteractsWithMail.php
index 54f90e3..8064e5d 100644
--- a/src/Testing/InteractsWithMail.php
+++ b/src/Testing/InteractsWithMail.php
@@ -132,7 +132,7 @@ protected function seeInSubjects($subjects)
         $subjects = (array) $subjects;
 
         foreach ($subjects as $subject) {
-            $this->assertTrue(in_array($subject, $this->mailer->subjects()->all()));
+            $this->assertTrue(in_array($subject, $this->getMailer()->subjects()->all()));
         }
     }