diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index 738304193f..0a4dbbbd94 100644
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -1016,7 +1016,7 @@ def format_resolution(format, default='unknown'):
     def list_formats(self, info_dict):
         def format_note(fdict):
             res = u''
-            if f.get('ext') in ['f4f', 'f4m']:
+            if fdict.get('ext') in ['f4f', 'f4m']:
                 res += u'(unsupported) '
             if fdict.get('format_note') is not None:
                 res += fdict['format_note'] + u' '