diff --git a/web_view.py b/web_view.py
index c670732..0f137b8 100755
--- a/web_view.py
+++ b/web_view.py
@@ -592,6 +592,10 @@ def trip_page(start: str) -> str:
 @app.route("/trip/<start>/debug")
 def trip_debug_page(start: str) -> str:
     """Trip debug page showing raw trip object data."""
+
+    if not flask.g.user.is_authenticated:
+        flask.abort(401)
+
     route_distances = agenda.travel.load_route_distances(app.config["DATA_DIR"])
     trip_list = get_trip_list(route_distances)