diff --git a/lib/gitlab/email/attachment_uploader.rb b/lib/gitlab/email/attachment_uploader.rb
index 0c0f50f2751..32cece8316b 100644
--- a/lib/gitlab/email/attachment_uploader.rb
+++ b/lib/gitlab/email/attachment_uploader.rb
@@ -1,6 +1,6 @@
 module Gitlab
   module Email
-    module AttachmentUploader
+    class AttachmentUploader
       attr_accessor :message
 
       def initialize(message)
diff --git a/lib/gitlab/email/receiver.rb b/lib/gitlab/email/receiver.rb
index c46fce6afe2..7160af29089 100644
--- a/lib/gitlab/email/receiver.rb
+++ b/lib/gitlab/email/receiver.rb
@@ -76,7 +76,7 @@ module Gitlab
       end
 
       def add_attachments(reply)
-        attachments = AttachmentUploader.new(message).execute(project)
+        attachments = Email::AttachmentUploader.new(message).execute(sent_notification.project)
 
         attachments.each do |link|
           text = "[#{link[:alt]}](#{link[:url]})"
@@ -84,6 +84,8 @@ module Gitlab
 
           reply << "\n\n#{text}"
         end
+
+        reply
       end
 
       def create_note(reply)