diff --git a/test/test_InfoExtractor.py b/test/test_InfoExtractor.py
index bc89b2955..6b144e7fa 100644
--- a/test/test_InfoExtractor.py
+++ b/test/test_InfoExtractor.py
@@ -324,7 +324,7 @@ def test_search_json_ld_realworld(self):
 "thumbnail_url": "//www.nobelprize.org/images/12693-landscape-medium-gallery.jpg"
 }</script>''',
                 {
-                    'thumbnails': [{'url': 'https://www.nobelprize.org/images/12693-landscape-medium-gallery.jpg'}],
+                    'thumbnails': [{'url': '//www.nobelprize.org/images/12693-landscape-medium-gallery.jpg'}],
                 },
                 {},
             ),
diff --git a/yt_dlp/extractor/common.py b/yt_dlp/extractor/common.py
index d5607296d..92f97dcc1 100644
--- a/yt_dlp/extractor/common.py
+++ b/yt_dlp/extractor/common.py
@@ -1676,7 +1676,7 @@ def extract_video_object(e):
                 'title': unescapeHTML(e.get('name')),
                 'description': unescapeHTML(e.get('description')),
                 'thumbnails': [{'url': unescapeHTML(url)}
-                               for url in variadic(traverse_obj(e, 'thumbnailUrl', 'thumbnailURL'))
+                               for url in variadic(traverse_obj(e, 'thumbnailUrl', 'thumbnailURL', 'thumbnail_url'))
                                if url_or_none(url)],
                 'duration': parse_duration(e.get('duration')),
                 'timestamp': unified_timestamp(e.get('uploadDate')),