diff --git a/searx/webapp.py b/searx/webapp.py
index 9f5a004b..8c1d57ac 100755
--- a/searx/webapp.py
+++ b/searx/webapp.py
@@ -647,7 +647,7 @@ def search():
             # removing html content and whitespace duplications
             result['title'] = ' '.join(html_to_text(result['title']).strip().split())
 
-        if 'url' in result and !('pretty_url' in result):
+        if 'url' in result and 'pretty_url' not in result:
             result['pretty_url'] = prettify_url(result['url'])
 
         # TODO, check if timezone is calculated right