diff --git a/aiod_registry/schema.py b/aiod_registry/schema.py
index 3a5cac6..4ebafca 100644
--- a/aiod_registry/schema.py
+++ b/aiod_registry/schema.py
@@ -232,6 +232,7 @@ def fill_empty_params(self):
             for task in version.tasks.values():
                 if task.params is None:
                     task.params = self.params
+        return self
 
 
 if __name__ == "__main__":