diff --git a/internetarchive/files.py b/internetarchive/files.py
index c8029469..3ddcfa98 100644
--- a/internetarchive/files.py
+++ b/internetarchive/files.py
@@ -28,6 +28,7 @@
 import socket
 import sys
 from contextlib import nullcontext, suppress
+from datetime import datetime, timezone
 from urllib.parse import quote
 
 from requests.exceptions import (
@@ -298,11 +299,17 @@ def download(self, file_path=None, verbose=None, ignore_existing=None,
             else:
                 raise exc
 
+        # Get timestamp from Last-Modified header
+        time_str = response.headers["Last-Modified"]
+        last_updated_pattern = "%a, %d %b %Y %H:%M:%S %Z"
+        dt = datetime.strptime(time_str, last_updated_pattern).replace(tzinfo=timezone.utc)
+        last_modified = int(dt.timestamp())
+
         # Set mtime with mtime from files.xml.
         if not no_change_timestamp:
             # If we want to set the timestamp to that of the original archive...
             with suppress(OSError):  # Probably file-like object, e.g. sys.stdout.
-                os.utime(file_path.encode('utf-8'), (0, self.mtime))
+                os.utime(file_path.encode('utf-8'), (0, last_modified))
 
         msg = f'downloaded {self.identifier}/{self.name} to {file_path}'
         log.info(msg)
diff --git a/internetarchive/item.py b/internetarchive/item.py
index 18a2d072..d49c6b5f 100644
--- a/internetarchive/item.py
+++ b/internetarchive/item.py
@@ -1106,10 +1106,10 @@ def _build_request():
                 return response
             except HTTPError as exc:
                 try:
-                    msg = get_s3_xml_text(exc.response.content)
+                    msg = get_s3_xml_text(exc.response.content)  # type: ignore
                 except ExpatError:  # probably HTTP 500 error and response is invalid XML
                     msg = ('IA S3 returned invalid XML '
-                           f'(HTTP status code {exc.response.status_code}). '
+                           f'(HTTP status code {exc.response.status_code}). '  # type: ignore
                            'This is a server side error which is either temporary, '
                            'or requires the intervention of IA admins.')