diff --git a/Dockerfile b/Dockerfile
index 9fccc95..9575a5c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -23,6 +23,9 @@ EXPOSE 80
 COPY requirements.txt /app/requirements.txt
 RUN pip install --no-cache-dir --upgrade -r /app/requirements.txt
 
+# set MODULE_NAME explicitly
+ENV MODULE_NAME=amarillo.main
+
 COPY ./amarillo /app/amarillo
 COPY enhancer.py /app
 COPY prestart.sh /app
diff --git a/README.md b/README.md
index ee57299..d78bad7 100644
--- a/README.md
+++ b/README.md
@@ -63,4 +63,4 @@ In the top directory, run `pytest amarillo/tests`.
 Based on [tiangolo/uvicorn-gunicorn:python3.9-slim](https://github.com/tiangolo/uvicorn-gunicorn-docker)
 
 - build `docker build -t amarillo .`
-- run `docker run --rm --name amarillo -p 8000:80 -e MODULE_NAME=amarillo.main -e MAX_WORKERS="1" -e ADMIN_TOKEN=$ADMIN_TOKEN -e RIDE2GO_TOKEN=$RIDE2GO_TOKEN -e TZ=Europe/Berlin -v $(pwd)/data:/app/data amarillo`
+- run `docker run --rm --name amarillo -p 8000:80 -e MAX_WORKERS="1" -e ADMIN_TOKEN=$ADMIN_TOKEN -e RIDE2GO_TOKEN=$RIDE2GO_TOKEN -e TZ=Europe/Berlin -v $(pwd)/data:/app/data amarillo`