diff --git a/sdk/python/kfp/_local_client.py b/sdk/python/kfp/_local_client.py
index 41312aa37fa..e12a466dd4a 100644
--- a/sdk/python/kfp/_local_client.py
+++ b/sdk/python/kfp/_local_client.py
@@ -454,7 +454,7 @@ def _run_group(
                 with open(_altered_list_file, "r") as f:
                     _param_values = json.load(f)
                 for index, _param_value in enumerate(_param_values):
-                    if isinstance(_param_values, object):
+                    if isinstance(_param_values, (dict, list)):
                         _param_value = json.dumps(_param_value)
                     stack[_loop_args.pattern] = _param_value
                     loop_run_name = "{run_name}/{loop_index}".format(