diff --git a/youtube_dl/extractor/twitch.py b/youtube_dl/extractor/twitch.py
index 78ee0115c..a3e816b76 100644
--- a/youtube_dl/extractor/twitch.py
+++ b/youtube_dl/extractor/twitch.py
@@ -192,7 +192,7 @@ class TwitchItemBaseIE(TwitchBaseIE):
             'title': info.get('title') or 'Untitled Broadcast',
             'description': info.get('description'),
             'duration': int_or_none(info.get('length')),
-            'thumbnail': info.get('preview'),
+            'thumbnail': info.get('preview').get('large'),
             'uploader': info.get('channel', {}).get('display_name'),
             'uploader_id': info.get('channel', {}).get('name'),
             'timestamp': parse_iso8601(info.get('recorded_at')),