diff --git a/src/core/models/schedules.py b/src/core/models/schedules.py
index e632486237c40e98b93ad6542e5ea1a6156e0618..8dfcc08519cccec359f002bb2400028f63d5c75f 100644
--- a/src/core/models/schedules.py
+++ b/src/core/models/schedules.py
@@ -75,7 +75,7 @@ class ScheduleSource(models.Model):
 
     @property
     def import_configuration_masked(self):
-        if 'auth' in self.import_configuration:
+        if self.import_configuration and 'auth' in self.import_configuration:
             return {**self.import_configuration, 'auth': '********'}
         return self.import_configuration