diff --git a/NOTES.md b/NOTES.md
index fa8d175..22fbdfb 100644
--- a/NOTES.md
+++ b/NOTES.md
@@ -70,4 +70,16 @@ cd NNG4 && python3 ./gameserver.py
 # Test docker
 ```
 docker run --runtime=runsc --network=none --rm -it nng4:latest
+```
+
+# Running on port 80
+
+## Set environment variable
+```
+export PORT=80
+```
+## Enable running on port 80:
+```
+sudo apt-get install libcap2-bin
+sudo setcap cap_net_bind_service=+ep `readlink -f \`which node\``
 ```
\ No newline at end of file