diff --git a/dagfactory/dagbuilder.py b/dagfactory/dagbuilder.py
index 856b841c..44336a10 100644
--- a/dagfactory/dagbuilder.py
+++ b/dagfactory/dagbuilder.py
@@ -637,66 +637,61 @@ def make_task_groups(
                 task_group_conf["group_id"] = task_group_name
                 task_group_conf["dag"] = dag
 
-                if version.parse(AIRFLOW_VERSION) >= version.parse("2.2.0"):
+                if version.parse(AIRFLOW_VERSION) >= version.parse(
+                    "2.2.0"
+                ) and isinstance(task_group_conf.get("default_args"), dict):
                     # https://github.com/apache/airflow/pull/16557
-                    if isinstance(task_group_conf.get("default_args"), dict):
-                        if utils.check_dict_key(
-                            task_group_conf["default_args"], "on_success_callback"
+                    if utils.check_dict_key(
+                        task_group_conf["default_args"], "on_success_callback"
+                    ):
+                        if isinstance(
+                            task_group_conf["default_args"]["on_success_callback"],
+                            str,
                         ):
-                            if isinstance(
-                                task_group_conf["default_args"]["on_success_callback"],
-                                str,
-                            ):
-                                task_group_conf["default_args"][
-                                    "on_success_callback"
-                                ]: Callable = import_string(
-                                    task_group_conf["default_args"][
-                                        "on_success_callback"
-                                    ]
-                                )
-
-                        if utils.check_dict_key(
-                            task_group_conf["default_args"], "on_execute_callback"
+                            task_group_conf["default_args"][
+                                "on_success_callback"
+                            ]: Callable = import_string(
+                                task_group_conf["default_args"]["on_success_callback"]
+                            )
+
+                    if utils.check_dict_key(
+                        task_group_conf["default_args"], "on_execute_callback"
+                    ):
+                        if isinstance(
+                            task_group_conf["default_args"]["on_execute_callback"],
+                            str,
                         ):
-                            if isinstance(
-                                task_group_conf["default_args"]["on_execute_callback"],
-                                str,
-                            ):
-                                task_group_conf["default_args"][
-                                    "on_execute_callback"
-                                ]: Callable = import_string(
-                                    task_group_conf["default_args"][
-                                        "on_execute_callback"
-                                    ]
-                                )
-
-                        if utils.check_dict_key(
-                            task_group_conf["default_args"], "on_failure_callback"
+                            task_group_conf["default_args"][
+                                "on_execute_callback"
+                            ]: Callable = import_string(
+                                task_group_conf["default_args"]["on_execute_callback"]
+                            )
+
+                    if utils.check_dict_key(
+                        task_group_conf["default_args"], "on_failure_callback"
+                    ):
+                        if isinstance(
+                            task_group_conf["default_args"]["on_failure_callback"],
+                            str,
                         ):
-                            if isinstance(
-                                task_group_conf["default_args"]["on_failure_callback"],
-                                str,
-                            ):
-                                task_group_conf["default_args"][
-                                    "on_failure_callback"
-                                ]: Callable = import_string(
-                                    task_group_conf["default_args"][
-                                        "on_failure_callback"
-                                    ]
-                                )
-
-                        if utils.check_dict_key(
-                            task_group_conf["default_args"], "on_retry_callback"
+                            task_group_conf["default_args"][
+                                "on_failure_callback"
+                            ]: Callable = import_string(
+                                task_group_conf["default_args"]["on_failure_callback"]
+                            )
+
+                    if utils.check_dict_key(
+                        task_group_conf["default_args"], "on_retry_callback"
+                    ):
+                        if isinstance(
+                            task_group_conf["default_args"]["on_retry_callback"],
+                            str,
                         ):
-                            if isinstance(
-                                task_group_conf["default_args"]["on_retry_callback"],
-                                str,
-                            ):
-                                task_group_conf["default_args"][
-                                    "on_retry_callback"
-                                ]: Callable = import_string(
-                                    task_group_conf["default_args"]["on_retry_callback"]
-                                )
+                            task_group_conf["default_args"][
+                                "on_retry_callback"
+                            ]: Callable = import_string(
+                                task_group_conf["default_args"]["on_retry_callback"]
+                            )
 
                     task_group = TaskGroup(
                         **{