diff --git a/src/llamafactory/data/data_utils.py b/src/llamafactory/data/data_utils.py
index ebc500c54..144dbde1d 100644
--- a/src/llamafactory/data/data_utils.py
+++ b/src/llamafactory/data/data_utils.py
@@ -196,7 +196,7 @@ def read_cloud_json(cloud_path: str) -> list[Any]:
 
     # filter out non-JSON files
     files = [x["Key"] for x in fs.listdir(cloud_path)] if fs.isdir(cloud_path) else [cloud_path]
-    files = filter(lambda file: file.endswith(".json") or file.endswith(".jsonl"), files)
+    files = list(filter(lambda file: file.endswith(".json") or file.endswith(".jsonl"), files))
     if not files:
         raise ValueError(f"No JSON/JSONL files found in the specified path: {cloud_path}.")