diff --git a/files/helpers/sanitize.py b/files/helpers/sanitize.py
index 81898d7338..fa0976330a 100644
--- a/files/helpers/sanitize.py
+++ b/files/helpers/sanitize.py
@@ -683,7 +683,7 @@ def filter_emojis_only(title, golden=True, count_emojis=False, obj=None, author=
 	return title
 
 def is_whitelisted(domain, k):
-	if k.lower.startswith('utm_'):
+	if k.lower().startswith('utm_'):
 		return False
 
 	if domain not in {'youtube.com','reddit.com','twitter.com','msn.com','wsj.com','tiktok.com','forbes.com','dailymail.co.uk','facebook.com','spotify.com','nytimes.com','businessinsider.com','instagram.com','yahoo.com','thedailybeast.com','nypost.com','newsweek.com','bloomberg.com','quora.com','nbcnews.com','reuters.com','tmz.com','cnbc.com','marketwatch.com','thetimes.co.uk','sfchronicle.com','washingtonpost.com','cbsnews.com','foxnews.com','bbc.com','bbc.co.uk','ifunny.co','independent.co.uk'}: