diff --git a/src/app.py b/src/app.py
index 9cde5c3..be58867 100644
--- a/src/app.py
+++ b/src/app.py
@@ -27,10 +27,13 @@ def worker():
     filename = "{}@{}.json".format(account_info["username"], domain).lower()
     filepath = os.path.join(base_dir, os.path.basename(filename.lower()))
 
+    now = datetime.datetime.now().timestamp()
     if is_lambda:
-        s3.get_file(filename, filepath)
+        _, last_modified = s3.get_file(filename, filepath)
+    else:
+        last_modified = os.path.getmtime(filepath) if os.path.isfile(filepath) else None
 
-    if (os.path.isfile(filepath) and datetime.datetime.now().timestamp() - os.path.getmtime(filepath) < 60 * 60 * 24):
+    if (os.path.isfile(filepath) and last_modified is not None and now - last_modified < 60 * 60 * 24):
         print("モデルは再生成されません")
     else:
         exportModel.generateAndExport(mastodonTool.loadMastodonAPI(domain, read_access_token, account_info['id'], params), filepath)
diff --git a/src/s3.py b/src/s3.py
index 3030fe5..3545adb 100644
--- a/src/s3.py
+++ b/src/s3.py
@@ -9,12 +9,14 @@
 
 def get_file(key, file_path):
     try:
-        s3.Bucket(os.environ["S3_BUCKET"]).download_file(key, file_path)
+        bucketName = os.environ["S3_BUCKET"]
+        object_summery = s3.ObjectSummary(bucketName, key)
+        s3.Bucket(bucketName).download_file(key, file_path)
         print("File downloaded: {} to {}".format(key, file_path))
+        return True, object_summery.last_modified.timestamp()
     except ClientError:
         print("File not found: {}".format(key))
-        return False
-    return True
+    return False, None
 
 
 def put_file(key, file_path):