diff --git a/src/Mail/Mailer.php b/src/Mail/Mailer.php
index a47f058de..5569aa6e6 100644
--- a/src/Mail/Mailer.php
+++ b/src/Mail/Mailer.php
@@ -217,7 +217,14 @@ protected function addContent($message, $view, $plain, $raw, $data)
                 $text = $result['text'];
             }
 
-            if ($subject = array_get($result['settings'], 'subject')) {
+            /*
+             * Subject
+             */
+            $customSubject = $message->getSwiftMessage()->getSubject();
+            if (
+                empty($customSubject) &&
+                ($subject = array_get($result['settings'], 'subject'))
+            ) {
                 $message->subject($subject);
             }
         }