diff --git a/youtube_dl/extractor/archiveorg.py b/youtube_dl/extractor/archiveorg.py
index f04eefe9f..f34f32b7e 100644
--- a/youtube_dl/extractor/archiveorg.py
+++ b/youtube_dl/extractor/archiveorg.py
@@ -51,8 +51,7 @@ class ArchiveOrgIE(InfoExtractor):
             return metadata.get(field, [None])[0]
 
         def convert_relative_to_absolute_thumbnail(metadata):
-            if not metadata['thumbnail'].startswith('http'):
-                metadata.update({'thumbnail': urljoin('http://archive.org', metadata.get('thumbnail'))})
+            metadata.update({'thumbnail': urljoin('http://archive.org', metadata.get('thumbnail'))})
 
         metadata = self._download_json(
             'http://archive.org/details/' + video_id, video_id, query={