diff --git a/README.md b/README.md
index cbdff42..0f6f45d 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ Various tools to monitor Docker containers
 
 ## Setup
 
-Set the DOCKER_GUID so the container has permission to access the socket
+Set the `DOCKER_GUID` so the container has permission to access the socket. This ensures that the telegraf container will have read access on the Docker socket.
 
 ```shell
 export DOCKER_GUID=$(getent group docker | awk -F ':' '{print $3}')
diff --git a/docker-compose.yml b/docker-compose.yml
index 3b25b0d..83987e0 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -3,7 +3,7 @@ services:
   telegraf-docker:
     image: telegraf
     restart: unless-stopped
-    user: root:$DOCKER_GUID
+    user: root:${DOCKER_GUID}
     env_file:
       - .env
     volumes: