diff --git a/jupyter_server_proxy/standalone/__init__.py b/jupyter_server_proxy/standalone/__init__.py
index 521d733d..199b1f05 100644
--- a/jupyter_server_proxy/standalone/__init__.py
+++ b/jupyter_server_proxy/standalone/__init__.py
@@ -1,4 +1,4 @@
-from __future__ import annotations  # For Python 3.8 compatibility
+from __future__ import annotations  # Allows type subscripts (like tuple[str, int]) in Python 3.8
 
 import argparse
 import logging
diff --git a/jupyter_server_proxy/standalone/activity.py b/jupyter_server_proxy/standalone/activity.py
index f08085e0..8028ca7d 100644
--- a/jupyter_server_proxy/standalone/activity.py
+++ b/jupyter_server_proxy/standalone/activity.py
@@ -10,7 +10,7 @@
 async def notify_activity():
     """
     Regularly notify JupyterHub of activity.
-    See `jupyrehub/singleuser/extensions#L396`
+    See https://github.com/jupyterhub/jupyterhub/blob/4.x/jupyterhub/singleuser/extension.py#L389
     """
 
     client = httpclient.AsyncHTTPClient()
diff --git a/jupyter_server_proxy/standalone/proxy.py b/jupyter_server_proxy/standalone/proxy.py
index 24ea63e9..22fc3660 100644
--- a/jupyter_server_proxy/standalone/proxy.py
+++ b/jupyter_server_proxy/standalone/proxy.py
@@ -1,4 +1,4 @@
-from __future__ import annotations  # For Python 3.8 compatibility
+from __future__ import annotations  # Allows type subscripts (like tuple[str, int]) in Python 3.8
 
 import os
 import re
@@ -81,7 +81,7 @@ def get_timeout(self):
 
 
 def configure_ssl():
-    # See jupyter_server/serverapp:init_webapp
+    # See https://github.com/jupyter-server/jupyter_server/blob/v2.0.0/jupyter_server/serverapp.py#L2053-L2073
     keyfile = os.environ.get("JUPYTERHUB_SSL_KEYFILE", "")
     certfile = os.environ.get("JUPYTERHUB_SSL_CERTFILE", "")
     client_ca = os.environ.get("JUPYTERHUB_SSL_CLIENT_CA", "")