diff --git a/backend/app/dav/caldav.py b/backend/app/dav/caldav.py
index cc92f01..6c5358e 100644
--- a/backend/app/dav/caldav.py
+++ b/backend/app/dav/caldav.py
@@ -440,6 +440,9 @@ def _extract_time_range(root: ET.Element):
 @dav_bp.route('/<username>/<cal_part>/<filename>', methods=['GET', 'HEAD'])
 @basic_auth
 def get_event(username, cal_part, filename):
+    if cal_part.startswith('ab-'):
+        from .carddav import ab_get
+        return ab_get(username=username, ab_part=cal_part, filename=filename)
     user: User = request.dav_user
     if username != user.username:
         return Response('', 403)
@@ -465,6 +468,9 @@ def get_event(username, cal_part, filename):
 @dav_bp.route('/<username>/<cal_part>/<filename>', methods=['PUT'])
 @basic_auth
 def put_event(username, cal_part, filename):
+    if cal_part.startswith('ab-'):
+        from .carddav import ab_put
+        return ab_put(username=username, ab_part=cal_part, filename=filename)
     user: User = request.dav_user
     if username != user.username:
         return Response('', 403)
@@ -519,6 +525,9 @@ def put_event(username, cal_part, filename):
 @dav_bp.route('/<username>/<cal_part>/<filename>', methods=['DELETE'])
 @basic_auth
 def delete_event(username, cal_part, filename):
+    if cal_part.startswith('ab-'):
+        from .carddav import ab_delete
+        return ab_delete(username=username, ab_part=cal_part, filename=filename)
     user: User = request.dav_user
     if username != user.username:
         return Response('', 403)
@@ -539,6 +548,9 @@ def delete_event(username, cal_part, filename):
 @dav_bp.route('/<username>/<cal_part>', methods=['DELETE'])
 @basic_auth
 def delete_calendar(username, cal_part):
+    if cal_part.startswith('ab-'):
+        from .carddav import ab_delete_collection
+        return ab_delete_collection(username=username, ab_part=cal_part)
     user: User = request.dav_user
     if username != user.username:
         return Response('', 403)