diff --git a/app/models/attachment.rb b/app/models/attachment.rb
index 4a6580a7a..380e98e02 100644
--- a/app/models/attachment.rb
+++ b/app/models/attachment.rb
@@ -259,7 +259,7 @@ class Attachment < ActiveRecord::Base
   end
 
   def office_conver
-    return unless %w(Project Course).included? (self.container_type)
+    return unless %w(Project Course).include? (self.container_type)
     saved_path = File.join(Rails.root, "files", "convered_office")
     unless Dir.exist?(saved_path)
       Dir.mkdir(saved_path)