diff --git a/lib/mpw/mpw.rb b/lib/mpw/mpw.rb
index 9197307..b8f315c 100644
--- a/lib/mpw/mpw.rb
+++ b/lib/mpw/mpw.rb
@@ -74,6 +74,8 @@ class MPW
 				          )
 			end
 		end
+
+		add_key(@key) if @keys[@key].nil?
 	rescue Exception => e
 		raise "#{I18n.t('error.mpw_file.read_data')}\n#{e}"
 	end