diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index 582ea67f5..486985744 100755
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -583,7 +583,7 @@ class YoutubeDL(object):
             autonumber_templ = '%0' + str(autonumber_size) + 'd'
             template_dict['autonumber'] = autonumber_templ % self._num_downloads
             if template_dict.get('playlist_index') is not None:
-                template_dict['playlist_index'] = '%0*d' % (len(str(template_dict['n_entries'])), (int(template_dict['playlist_index']) + int(self.params.get('playlist_index_offset'))))
+                template_dict['playlist_index'] = '%0*d' % (len(str(template_dict['n_entries'])), (template_dict['playlist_index'] + int(self.params.get('playlist_index_offset'))))
             if template_dict.get('resolution') is None:
                 if template_dict.get('width') and template_dict.get('height'):
                     template_dict['resolution'] = '%dx%d' % (template_dict['width'], template_dict['height'])