diff --git a/metaflow/plugins/airflow/sensors/external_task_sensor.py b/metaflow/plugins/airflow/sensors/external_task_sensor.py
index c599a05b4a..aa5fe454e0 100644
--- a/metaflow/plugins/airflow/sensors/external_task_sensor.py
+++ b/metaflow/plugins/airflow/sensors/external_task_sensor.py
@@ -28,27 +28,27 @@ class ExternalTaskSensorDecorator(AirflowSensorDecorator):
         Time, in seconds before the task times out and fails. (Default: 3600)
     poke_interval : int
         Time in seconds that the job should wait in between each try. (Default: 60)
-    mode : string
+    mode : str
         How the sensor operates. Options are: { poke | reschedule }. (Default: "poke")
     exponential_backoff : bool
         allow progressive longer waits between pokes by using exponential backoff algorithm. (Default: True)
-    pool : string
+    pool : str
         the slot pool this task should run in,
         slot pools are a way to limit concurrency for certain tasks. (Default:None)
     soft_fail : bool
         Set to true to mark the task as SKIPPED on failure. (Default: False)
-    name : string
+    name : str
         Name of the sensor on Airflow
-    description : string
+    description : str
         Description of sensor in the Airflow UI
-    external_dag_id : string
+    external_dag_id : str
         The dag_id that contains the task you want to wait for.
-    external_task_ids : List[string]
+    external_task_ids : List[str]
         The list of task_ids that you want to wait for.
         If None (default value) the sensor waits for the DAG. (Default: None)
-    allowed_states : List[string]
+    allowed_states : List[str]
         Iterable of allowed states, (Default: ['success'])
-    failed_states : List[string]
+    failed_states : List[str]
         Iterable of failed or dis-allowed states. (Default: None)
     execution_delta : datetime.timedelta
         time difference with the previous execution to look at,
diff --git a/metaflow/plugins/airflow/sensors/s3_sensor.py b/metaflow/plugins/airflow/sensors/s3_sensor.py
index 6fac6725d2..ff5b12be61 100644
--- a/metaflow/plugins/airflow/sensors/s3_sensor.py
+++ b/metaflow/plugins/airflow/sensors/s3_sensor.py
@@ -17,20 +17,20 @@ class S3KeySensorDecorator(AirflowSensorDecorator):
         Time, in seconds before the task times out and fails. (Default: 3600)
     poke_interval : int
         Time in seconds that the job should wait in between each try. (Default: 60)
-    mode : string
+    mode : str
         How the sensor operates. Options are: { poke | reschedule }. (Default: "poke")
     exponential_backoff : bool
         allow progressive longer waits between pokes by using exponential backoff algorithm. (Default: True)
-    pool : string
+    pool : str
         the slot pool this task should run in,
         slot pools are a way to limit concurrency for certain tasks. (Default:None)
     soft_fail : bool
         Set to true to mark the task as SKIPPED on failure. (Default: False)
-    name : string
+    name : str
         Name of the sensor on Airflow
-    description : string
+    description : str
         Description of sensor in the Airflow UI
-    bucket_key : str | List[str]
+    bucket_key : Union[str, List[str]]
         The key(s) being waited on. Supports full s3:// style url or relative path from root level.
         When it's specified as a full s3:// url, please leave `bucket_name` as None
     bucket_name : str
@@ -38,7 +38,7 @@ class S3KeySensorDecorator(AirflowSensorDecorator):
         When specified, all the keys passed to bucket_key refers to this bucket. (Default:None)
     wildcard_match : bool
         whether the bucket_key should be interpreted as a Unix wildcard pattern. (Default: False)
-    aws_conn_id : string
+    aws_conn_id : str
         a reference to the s3 connection on Airflow. (Default: None)
     verify : bool
         Whether or not to verify SSL certificates for S3 connection. (Default: None)
diff --git a/metaflow/plugins/aws/batch/batch_decorator.py b/metaflow/plugins/aws/batch/batch_decorator.py
index 33caaa2023..8b6de6c86a 100644
--- a/metaflow/plugins/aws/batch/batch_decorator.py
+++ b/metaflow/plugins/aws/batch/batch_decorator.py
@@ -79,7 +79,7 @@ class BatchDecorator(StepDecorator):
         The value for the size (in MiB) of the tmpfs mount for this step.
         This parameter maps to the `--tmpfs` option in Docker. Defaults to 50% of the
         memory allocated for this step.
-    tmpfs_path: string, optional, default None
+    tmpfs_path: str, optional, default None
         Path to tmpfs mount for this step. Defaults to /metaflow_temp.
     inferentia : int, default 0
         Number of Inferentia chips required for this step.