diff --git a/Dockerfile b/Dockerfile
index 92e6118..441453d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.11
+FROM python:3.11-slim
 
 WORKDIR /app
 COPY app.py .
@@ -6,11 +6,10 @@ COPY requirements.txt .
 
 RUN pip install --no-cache-dir -r requirements.txt
 
-# Environment variables
 ENV CALDAV_URL=""
 ENV PASSWORD=""
 ENV RA_API=""
 ENV RA_USER=""
 ENV CALENDAR_NAME=""
 
-CMD ["python3", "./app.py", "$CALDAV_URL", "$CALENDAR_NAME", "$USERNAME", "$PASSWORD", "$RA_API", "$RA_USER"]
+CMD python3 ./app.py "${CALDAV_URL}" ${CALENDAR_NAME}" "${USERNAME}" "${PASSWORD}" "${RA_API}" "${RA_USER}"