diff --git a/scenarionet/scripts/convert_nuplan.py b/scenarionet/scripts/convert_nuplan.py
index db863f2..9a280b4 100644
--- a/scenarionet/scripts/convert_nuplan.py
+++ b/scenarionet/scripts/convert_nuplan.py
@@ -17,6 +17,7 @@ if __name__ == '__main__':
                         help="The path of the dataset")
     parser.add_argument("--version", "-v", default='v1.1', help="version")
     parser.add_argument("--overwrite", action="store_true", help="If the dataset_path exists, overwrite it")
+    parser.add_argument("--num_workers", type=int, default=8, help="number of workers to use")
     args = parser.parse_args()
 
     force_overwrite = args.overwrite
@@ -36,4 +37,5 @@ if __name__ == '__main__':
         dataset_version=version,
         dataset_name=dataset_name,
         force_overwrite=force_overwrite,
+        num_workers=args.num_workers
     )
diff --git a/scenarionet/scripts/convert_nuscenes.py b/scenarionet/scripts/convert_nuscenes.py
index 263fb58..9bdbb65 100644
--- a/scenarionet/scripts/convert_nuscenes.py
+++ b/scenarionet/scripts/convert_nuscenes.py
@@ -17,6 +17,7 @@ if __name__ == '__main__':
                         help="The path of the dataset")
     parser.add_argument("--version", "-v", default='v1.0-mini',  help="version")
     parser.add_argument("--overwrite", action="store_true", help="If the dataset_path exists, overwrite it")
+    parser.add_argument("--num_workers", type=int, default=8, help="number of workers to use")
     args = parser.parse_args()
 
     force_overwrite = args.overwrite
@@ -34,5 +35,6 @@ if __name__ == '__main__':
         dataset_version=version,
         dataset_name=dataset_name,
         force_overwrite=force_overwrite,
-        nuscenes=nusc
+        nuscenes=nusc,
+        num_workers=args.num_workers
     )
diff --git a/scenarionet/scripts/convert_pg.py b/scenarionet/scripts/convert_pg.py
index 6c53650..74bea65 100644
--- a/scenarionet/scripts/convert_pg.py
+++ b/scenarionet/scripts/convert_pg.py
@@ -17,6 +17,7 @@ if __name__ == '__main__':
                         help="The path of the dataset")
     parser.add_argument("--version", "-v", default=metadrive.constants.DATA_VERSION,  help="version")
     parser.add_argument("--overwrite", action="store_true", help="If the dataset_path exists, overwrite it")
+    parser.add_argument("--num_workers", type=int, default=8, help="number of workers to use")
     args = parser.parse_args()
 
     force_overwrite = args.overwrite
@@ -33,5 +34,6 @@ if __name__ == '__main__':
         dataset_version=version,
         dataset_name=dataset_name,
         force_overwrite=force_overwrite,
-        env=env
+        env=env,
+        num_workers=args.num_workers
     )
diff --git a/scenarionet/scripts/convert_waymo.py b/scenarionet/scripts/convert_waymo.py
index 43ef132..7e6a6ce 100644
--- a/scenarionet/scripts/convert_waymo.py
+++ b/scenarionet/scripts/convert_waymo.py
@@ -16,6 +16,7 @@ if __name__ == '__main__':
                         help="The path of the dataset")
     parser.add_argument("--version", "-v", default='v1.2',  help="version")
     parser.add_argument("--overwrite", action="store_true", help="If the dataset_path exists, overwrite it")
+    parser.add_argument("--num_workers", type=int, default=8, help="number of workers to use")
     args = parser.parse_args()
 
     force_overwrite = args.overwrite
@@ -32,5 +33,6 @@ if __name__ == '__main__':
         output_path=output_path,
         dataset_version=version,
         dataset_name=dataset_name,
-        force_overwrite=force_overwrite
+        force_overwrite=force_overwrite,
+        num_workers=args.num_workers
     )
diff --git a/scenarionet/scripts/verify_dataset.py b/scenarionet/scripts/verify_dataset.py
index 3c3a8aa..9797190 100644
--- a/scenarionet/scripts/verify_dataset.py
+++ b/scenarionet/scripts/verify_dataset.py
@@ -10,5 +10,6 @@ if __name__ == '__main__':
     parser = argparse.ArgumentParser()
     parser.add_argument("--dataset_path", required=True, help="Dataset path, a directory")
     parser.add_argument("--result_save_dir", required=True, help="Dataset path, a directory")
+    parser.add_argument("--num_workers", type=int, default=8, help="number of workers to use")
     args = parser.parse_args()
-    verify_loading_into_metadrive(args.dataset_path, args.result_save_dir)
+    verify_loading_into_metadrive(args.dataset_path, args.result_save_dir,         num_workers=args.num_workers)