diff --git a/README.md b/README.md
index ee4055e..0acd1e1 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ source .venv/bin/activate
 python3 -m pip install --upgrade pip
 pip3 install -r requirements.txt
 export FLASK_ADDRESS='<headwind bluetooth address>'
+export FLASK_URL='<address and port to bind'
 python3 main.py
 ```