diff --git a/backend/app/__init__.py b/backend/app/__init__.py
index 20d1aeb..b2f2ccf 100644
--- a/backend/app/__init__.py
+++ b/backend/app/__init__.py
@@ -1,7 +1,7 @@
 import os
 from pathlib import Path
 
-from flask import Flask, redirect, send_from_directory
+from flask import Flask, Response, redirect, send_from_directory
 from flask_cors import CORS
 
 from app.config import Config
@@ -119,6 +119,24 @@ def create_app(config_class=Config):
         provide_automatic_options=False,
     )
 
+    # Root DAV discovery: DAVx5 und einige andere Clients probieren zuerst
+    # PROPFIND/OPTIONS auf / (nur Hostname), bevor sie /.well-known nutzen.
+    # Wir reagieren hier auch mit DAV-Properties.
+    def _root_dav():
+        if request.method == 'PROPFIND':
+            return dav_propfind(subpath='')
+        if request.method == 'OPTIONS':
+            return dav_options()
+        # GET/HEAD: SPA index handhabt das woanders - dieser View matcht nur DAV-Methoden
+        return Response('', 405)
+
+    app.add_url_rule(
+        '/', view_func=_root_dav,
+        endpoint='_root_dav',
+        methods=['PROPFIND', 'OPTIONS'],
+        provide_automatic_options=False,
+    )
+
     # iCal export (public, no auth)
     @app.route('/ical/<token>')
     def ical_export_route(token):