diff --git a/src/openscm_zenodo/cli/app.py b/src/openscm_zenodo/cli/app.py
index 1585f2e..d3cbac2 100644
--- a/src/openscm_zenodo/cli/app.py
+++ b/src/openscm_zenodo/cli/app.py
@@ -195,6 +195,10 @@ def upload_files_command(
     """
     Upload files to a Zenodo deposition
     """
+    if files_to_upload is None:
+        msg = "You must supply some files to upload"
+        raise ValueError(msg)
+
     zenoodo_interactor = ZenodoInteractor(
         token=token,
         zenodo_domain=zenodo_domain,
diff --git a/src/openscm_zenodo/zenodo.py b/src/openscm_zenodo/zenodo.py
index 6d32569..73984d7 100644
--- a/src/openscm_zenodo/zenodo.py
+++ b/src/openscm_zenodo/zenodo.py
@@ -8,7 +8,7 @@
 import json
 import logging
 import os.path
-from collections.abc import Iterable
+from collections.abc import Collection, Iterable
 from enum import Enum, auto
 from pathlib import Path
 from typing import Any, Optional, Union
@@ -499,7 +499,7 @@ def upload_file_to_bucket_url(
     def upload_files(
         self,
         deposition_id: str,
-        to_upload: Iterable[Path],
+        to_upload: Collection[Path],
         tqdm_kwargs: Optional[dict[str, Any]] = None,
         n_threads: int = 4,
     ) -> tuple[requests.models.Response, ...]:
@@ -610,7 +610,7 @@ def delete_deposition(self, deposition_id: str) -> None:
     def remove_files(
         self,
         deposition_id: str,
-        to_remove: Iterable[Path],
+        to_remove: Collection[Path],
         # # Off until parallelism works
         # n_threads: int = 4,
     ) -> tuple[requests.models.Response, ...]:
@@ -674,10 +674,12 @@ def remove_files_by_id(
             The response(s) from the file removal request(s)
         """
         # Wanted to do this in parallel, but weirdly flaky
-        responses = [
-            self.remove_file_id(deposition_id=deposition_id, to_remove_id=file_id)
-            for file_id in tqdm.tqdm(file_ids_to_remove, desc="Files to remove")
-        ]
+        responses = tuple(
+            [
+                self.remove_file_id(deposition_id=deposition_id, to_remove_id=file_id)
+                for file_id in tqdm.tqdm(file_ids_to_remove, desc="Files to remove")
+            ]
+        )
         # with concurrent.futures.ThreadPoolExecutor(max_workers=n_threads) as executor:
         #     futures = [
         #         executor.submit(