diff --git a/syng/sources/files.py b/syng/sources/files.py
index 20450f3..765aa8b 100644
--- a/syng/sources/files.py
+++ b/syng/sources/files.py
@@ -4,6 +4,7 @@ import asyncio
 import os
 from typing import Any, Optional
 from typing import Tuple
+from platformdirs import user_cache_dir
 
 from ..entry import Entry
 from .source import available_sources
@@ -20,7 +21,7 @@ class FilesSource(FileBasedSource):
     source_name = "files"
     config_schema = FileBasedSource.config_schema | {
         "dir": (str, "Directory to index", "."),
-        "index_file": (str, "Index file", "files-index"),
+        "index_file": (str, "Index file", os.path.join(user_cache_dir("syng"), "files-index")),
     }
 
     def __init__(self, config: dict[str, Any]):
diff --git a/syng/sources/s3.py b/syng/sources/s3.py
index f817166..66db816 100644
--- a/syng/sources/s3.py
+++ b/syng/sources/s3.py
@@ -9,6 +9,8 @@ import os
 from json import dump, load
 from typing import TYPE_CHECKING, Any, Optional, Tuple, cast
 
+from platformdirs import user_cache_dir
+
 try:
     from minio import Minio
 
@@ -44,7 +46,7 @@ class S3Source(FileBasedSource):
         "secure": (bool, "Use SSL", True),
         "bucket": (str, "Bucket of the s3", ""),
         "tmp_dir": (str, "Folder for\ntemporary download", "/tmp/syng"),
-        "index_file": (str, "Index file", "s3-index"),
+        "index_file": (str, "Index file", os.path.join(user_cache_dir("syng"), "s3-index")),
     }
 
     def __init__(self, config: dict[str, Any]):