diff --git a/webapp/app.py b/webapp/app.py
index 73e246f..a4355e3 100644
--- a/webapp/app.py
+++ b/webapp/app.py
@@ -11,6 +11,8 @@ from datetime import datetime
 from pathlib import Path
 from typing import Optional
 
+from urllib.parse import quote
+
 from fastapi import FastAPI, Depends, File, HTTPException, Request, Response, UploadFile, Cookie
 from fastapi.responses import FileResponse, StreamingResponse
 from fastapi.staticfiles import StaticFiles
@@ -280,9 +282,10 @@ async def download_ics(
     ics_path = DATA_DIR / "jobs" / job_id / filename
     if not ics_path.exists():
         raise HTTPException(404, "Fichier introuvable")
+    encoded = quote(filename, safe='')
     return FileResponse(
-        ics_path, media_type="text/calendar", filename=filename,
-        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
+        ics_path, media_type="text/calendar",
+        headers={"Content-Disposition": f"attachment; filename*=UTF-8''{encoded}"},
     )