diff --git a/youtube_dl/extractor/bbc.py b/youtube_dl/extractor/bbc.py
index a67ced3f6..76dfa0598 100644
--- a/youtube_dl/extractor/bbc.py
+++ b/youtube_dl/extractor/bbc.py
@@ -359,8 +359,12 @@ class BBCCoUkIE(InfoExtractor):
             try:
                 formatsAndSubtitles = self._download_media_selector_url(
                     mediaselector_url % programme_id, programme_id)
-                formats += formatsAndSubtitles[0]
-                subtitles += formatsAndSubtitles[1]
+                # formats should always be set, but just in case
+                if formatsAndSubtitles[0]:
+                    formats += formatsAndSubtitles[0]
+                # subtitles may never be set
+                if formatsAndSubtitles[1]:
+                    subtitles += formatsAndSubtitles[1]
             except BBCCoUkIE.MediaSelectionError as e:
                 if e.id in ('notukerror', 'geolocation', 'selectionunavailable'):
                     last_exception = e