diff --git a/searx/engines/youtube.py b/searx/engines/youtube.py
index 265f86af8..1331f480e 100644
--- a/searx/engines/youtube.py
+++ b/searx/engines/youtube.py
@@ -27,7 +27,7 @@ def response(resp):
title = result['title']['$t']
content = ''
if len(result['media$group']['media$thumbnail']):
- content += '' % (result['media$group']['media$thumbnail'][0]['url'])
+ content += ''.format(url, result['media$group']['media$thumbnail'][0]['url'])
if len(content):
content += '
' + result['content']['$t']
else: