diff --git a/src/app/services/downloader.py b/src/app/services/downloader.py
index d76e9df..e4af733 100644
--- a/src/app/services/downloader.py
+++ b/src/app/services/downloader.py
@@ -47,4 +47,4 @@ async def get_filename(book_id: int, file_type: str) -> Optional[str]:
         if response.status_code != 200:
             return None
 
-        return response.text
+        return response.text.encode("ascii", "ignore").decode("ascii")