diff --git a/district/tasks.py b/district/tasks.py
index 992bcdd96e17b873be0696fb19544c19e7109996..74a46f054681be1dec08cdf4a394a5059cfb45d2 100644
--- a/district/tasks.py
+++ b/district/tasks.py
@@ -68,6 +68,9 @@ def import_people_from_team(
 ):
     from .models import DistrictOctopusPersonPage, DistrictPeoplePage
 
+    if team_roles is None:
+        team_roles = []
+
     lock_file_name = os.path.join(
         tempfile.gettempdir(),
         f"{people_parent_page_id}-{team_shortcut}-{','.join(team_roles)}.people-from-team-import-lock",