diff --git a/src/calibre/library/save_to_disk.py b/src/calibre/library/save_to_disk.py
index a2b8b01a8f..858e4bf231 100644
--- a/src/calibre/library/save_to_disk.py
+++ b/src/calibre/library/save_to_disk.py
@@ -47,6 +47,7 @@ FORMAT_ARG_DESCS = dict(
         pubdate=_('The published date'),
         last_modified=_('The date when the metadata for this book record'
             ' was last modified'),
+        languages=_('The language(s) of this book'),
         id=_('The calibre internal id')
         )
 
@@ -283,7 +284,6 @@ def save_book_to_disk(id_, db, root, opts, length):
                 pass
 
 
-
 def do_save_book_to_disk(id_, mi, cover, plugboards,
         format_map, root, opts, length):
     from calibre.ebooks.metadata.meta import set_metadata