diff --git a/app/models/dmsf_folder.rb b/app/models/dmsf_folder.rb
index 1df026ac..127caeb7 100644
--- a/app/models/dmsf_folder.rb
+++ b/app/models/dmsf_folder.rb
@@ -338,7 +338,7 @@ class DmsfFolder < ActiveRecord::Base
   def self.is_column_on?(column)
     unless @@dmsf_columns
       @@dmsf_columns = Setting.plugin_redmine_dmsf['dmsf_columns']
-      @@dmsf_columns = DmsfFolder::DEFAULT_COLUMNS unless columns
+      @@dmsf_columns = DmsfFolder::DEFAULT_COLUMNS unless @@dmsf_columns
     end
     @@dmsf_columns.include? column
   end
@@ -353,7 +353,7 @@ class DmsfFolder < ActiveRecord::Base
   def self.get_column_position(column)
     unless @@dmsf_columns
       @@dmsf_columns = Setting.plugin_redmine_dmsf['dmsf_columns']
-      @@dmsf_columns = DmsfFolder::DEFAULT_COLUMNS unless columns
+      @@dmsf_columns = DmsfFolder::DEFAULT_COLUMNS unless @@dmsf_columns
     end
     pos = 0
     # 0 - checkbox