diff --git a/promptify/models/nlp/utils/utils.py b/promptify/models/nlp/utils/utils.py
index e2f46a5..12e1fe9 100644
--- a/promptify/models/nlp/utils/utils.py
+++ b/promptify/models/nlp/utils/utils.py
@@ -15,7 +15,7 @@ def download(url, destination_file):
         os.makedirs(path)
 
     destination_file = os.path.join(path, destination_file)
-
+    last_modified = ""
     if os.path.exists(destination_file):
         mtime = os.path.getmtime(destination_file)
         headers["if-modified-since"] = formatdate(mtime, usegmt=True)
@@ -31,7 +31,7 @@ def download(url, destination_file):
             for chunk in response.iter_content(chunk_size=1048576):
                 f.write(chunk)
 
-        if last_modified := response.headers.get("last-modified"):
+        if last_modified == response.headers.get("last-modified"):
             new_mtime = parsedate_to_datetime(last_modified).timestamp()
             os.utime(destination_file, times=(datetime.now().timestamp(), new_mtime))
     return destination_file