diff --git a/src/c3nav/editor/models/changeset.py b/src/c3nav/editor/models/changeset.py
index beafe349..0a90ca11 100644
--- a/src/c3nav/editor/models/changeset.py
+++ b/src/c3nav/editor/models/changeset.py
@@ -235,6 +235,7 @@ class ChangeSet(models.Model):
         """
         Returns a set with the primary keys of created objects from this model
         """
+        self.fill_changes_cache()
         if issubclass(model, ModelWrapper):
             model = model._obj
         return set(self.created_objects.get(model, {}).keys())