diff --git a/src/pretix/presale/utils.py b/src/pretix/presale/utils.py
index b4db29c08..65aabbdc9 100644
--- a/src/pretix/presale/utils.py
+++ b/src/pretix/presale/utils.py
@@ -223,7 +223,8 @@ def customer_logout(request):
 
 
 def _get_user_from_session_data(sessiondata):
-    if SESSION_KEY not in sessiondata: return None
+    if SESSION_KEY not in sessiondata:
+        return None
     user_id = get_user_model()._meta.pk.to_python(sessiondata[SESSION_KEY])
     backend_path = sessiondata[BACKEND_SESSION_KEY]
     if backend_path in settings.AUTHENTICATION_BACKENDS: