diff --git a/lms/envs/devstack.py b/lms/envs/devstack.py
index 11726120f86b..7f69641055af 100644
--- a/lms/envs/devstack.py
+++ b/lms/envs/devstack.py
@@ -561,6 +561,7 @@ def should_show_debug_toolbar(request):  # lint-amnesty, pylint: disable=missing
     'http://localhost:1991',  # frontend-app-admin-portal
     'http://localhost:1999',  # frontend-app-authn
     'http://localhost:18450',  # frontend-app-support-tools
+    'http://localhost:1994',  # frontend-app-gradebook
 ]