diff --git a/flask_sockets.py b/flask_sockets.py
index ce6ac89..ec23515 100644
--- a/flask_sockets.py
+++ b/flask_sockets.py
@@ -75,7 +75,7 @@ def decorator(f):
         return decorator
 
     def add_url_rule(self, rule, _, f, **options):
-        self.url_map.add(Rule(rule, endpoint=f))
+        self.url_map.add(Rule(rule, endpoint=f, websocket=True))
 
     def register_blueprint(self, blueprint, **options):
         """