diff --git a/roll/configs/worker_config.py b/roll/configs/worker_config.py
index 5ceb721a..57c8a49c 100644
--- a/roll/configs/worker_config.py
+++ b/roll/configs/worker_config.py
@@ -192,7 +192,7 @@ class WorkerConfig:
     )
 
     sequence_packing_args: SequencePackingConfig = field(
-        default= SequencePackingConfig(),
+        default_factory= SequencePackingConfig,
         metadata={
             "help": "Sequence packing related arguments "
         }