diff --git a/templates/pdns-letsencrypt.py.j2 b/templates/pdns-letsencrypt.py.j2
index 019fa4a..6ce855e 100644
--- a/templates/pdns-letsencrypt.py.j2
+++ b/templates/pdns-letsencrypt.py.j2
@@ -27,7 +27,8 @@ def get_challenge(db, path):
 
 def add_challenge(db, path, value):
 	c = db.cursor()
-	c.execute('REPLACE INTO challenges (q, value) VALUES(?, ?)', (path,value,))
+	c.execute('INSERT INTO challenges (q, value) VALUES(?, ?)', (path,value,))
+	c.execute("DELETE FROM challenges WHERE timestamp < strftime('%s', datetime('now','-2 day'))")
 	db.commit()
 
 def main_query():