diff --git a/po/ja.po b/po/ja.po
index 5bb49f0a7..1aca7c72f 100644
--- a/po/ja.po
+++ b/po/ja.po
@@ -1068,7 +1068,7 @@ msgstr "カラムを削除中"
 
 #: js/messages.php:67
 msgid "Adding Primary Key"
-msgstr ""
+msgstr "主キーの追加中"
 
 #: js/messages.php:68 libraries/relation.lib.php:87 pmd_general.php:386
 #: pmd_general.php:543 pmd_general.php:591 pmd_general.php:667