diff --git a/README.md b/README.md
index 7fa3943f0..028c2b0f3 100644
--- a/README.md
+++ b/README.md
@@ -66,7 +66,7 @@ Run Promgen using the following command.
 
 ```bash
 # Run Promgen web worker. This is typically balanced behind an NGINX instance
-docker run --rm -p 8000:8000 -v ~/.config/promgen:/etc/promgen/ line/promgen
+docker run --rm -p 8000:8000 -e ALLOWED_HOSTS=* -v ~/.config/promgen:/etc/promgen/ line/promgen
 
 # Run Promgen celery worker. Make sure to run it on the same machine as your Prometheus server to manage the config settings
 docker run --rm -v ~/.config/promgen:/etc/promgen/ -v /etc/prometheus:/etc/prometheus line/promgen worker