diff --git a/jupyterhub/handlers/pages.py b/jupyterhub/handlers/pages.py
index 1962f74a..3e6f40f4 100644
--- a/jupyterhub/handlers/pages.py
+++ b/jupyterhub/handlers/pages.py
@@ -28,7 +28,7 @@ class RootHandler(BaseHandler):
     """
     def get(self):
         next_url = self.get_argument('next', '')
-        if not next_url.startswith('/'):
+        if next_url and not next_url.startswith('/'):
             self.log.warning("Disallowing redirect outside JupyterHub: %r", next_url)
             next_url = ''
         if next_url and next_url.startswith(url_path_join(self.base_url, 'user/')):