diff --git a/mailman_sync.py b/mailman_sync.py
index c125b62..a111faa 100755
--- a/mailman_sync.py
+++ b/mailman_sync.py
@@ -134,11 +134,11 @@ def main(
     expected_lists = r.json()
 
     domain = mailman_client.get_domain(mail_host)
-    existing_lists = {list.list_name: list for list in domain.get_lists()}
+    existing_lists = {list.list_name.lower(): list for list in domain.get_lists()}
 
     for name, props in expected_lists.items():
-        if name in existing_lists:
-            list = existing_lists[name]
+        if name.lower() in existing_lists:
+            list = existing_lists[name.lower()]
         elif dry_run:
             print(f"Skipping non-existing list {name} in dry run mode")
             continue