diff --git a/po/ja.po b/po/ja.po
index 7f9e33ea9..c2354c718 100644
--- a/po/ja.po
+++ b/po/ja.po
@@ -1389,7 +1389,7 @@ msgstr "水"
 
 #: js/messages.php:190
 msgid "Thursday"
-msgstr ""
+msgstr "木"
 
 #: js/messages.php:191
 #, fuzzy