diff --git a/src/calibre/ebooks/metadata/epub.py b/src/calibre/ebooks/metadata/epub.py
index d08d40080d..25f74b99c9 100644
--- a/src/calibre/ebooks/metadata/epub.py
+++ b/src/calibre/ebooks/metadata/epub.py
@@ -117,6 +117,8 @@ def option_parser():
                       help=_('The series to which this book belongs'))
     parser.add_option('--series-index', default=None,
                       help=_('The series index'))
+    parser.add_option('--language', default=None,
+                      help=_('The book language'))
     return parser
 
 def main(args=sys.argv):
@@ -146,6 +148,9 @@ def main(args=sys.argv):
     if opts.series_index:
         mi.series_index = opts.series_index
         changed = True
+    if opts.language is not None:
+        mi.language = opts.language
+        changed = True
     
     if changed:
         stream.seek(0)