diff --git a/roles/mailman3/files/mailman-sar.py b/roles/mailman3/files/mailman-sar.py
index 4fc3b9896c..4a6e53b1ef 100644
--- a/roles/mailman3/files/mailman-sar.py
+++ b/roles/mailman3/files/mailman-sar.py
@@ -13,6 +13,7 @@ import os
 import sys
 
 from configparser import ConfigParser
+from six.moves.urllib.parse import urljoin
 import requests
 
 config = ConfigParser()