diff --git a/ochintin-daicho.cabal b/ochintin-daicho.cabal
--- a/ochintin-daicho.cabal
+++ b/ochintin-daicho.cabal
@@ -1,5 +1,5 @@
 name:                ochintin-daicho
-version:             0.3.4.1
+version:             0.3.4.2
 synopsis:            A module to manage payroll books for Japanese companies.
 description:
     A module to manage payroll books for Japanese companies. This enable to export data to tax withholding book, etc...
diff --git a/src/Business/OchintinDaicho/Person.hs b/src/Business/OchintinDaicho/Person.hs
--- a/src/Business/OchintinDaicho/Person.hs
+++ b/src/Business/OchintinDaicho/Person.hs
@@ -20,6 +20,7 @@
   ) where
 
 import Business.OchintinDaicho (Person(..))
+import Data.Monoid ((<>))
 import Data.Text (Text)
 import qualified Data.Text as T
 import qualified Data.Text.IO as T