diff --git a/app/models/dmsf_file.rb b/app/models/dmsf_file.rb
index 5c35a1ac..b1fd4c29 100644
--- a/app/models/dmsf_file.rb
+++ b/app/models/dmsf_file.rb
@@ -82,6 +82,15 @@ class DmsfFile < ActiveRecord::Base
   @@previews_storage_path = File.join(Rails.root, 'tmp', 'dmsf_previews')
 
   before_create :default_values
+  
+  def visible?
+    if self.respond_to?(:type)
+      if /^folder/.match?(type)
+        return DmsfFolder.visible.where(id: self.id).exists?
+      end
+    end
+    true
+  end
 
   def default_values
     if Setting.plugin_redmine_dmsf['dmsf_default_notifications'].present? && (!dmsf_folder || !dmsf_folder.system)