diff --git a/Dockerfile b/Dockerfile
index be74dd3..7b03181 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,6 +7,6 @@ ARG VERSION=2.43.0
 
 RUN curl -L https://github.com/prometheus/prometheus/releases/download/v${VERSION}/prometheus-${VERSION}.linux-amd64.tar.gz | tar zxvf - --strip-components 1
 
-COPY default_prometheus_variables.sh start.sh /app/pkg/
+COPY env.sh.template start.sh /app/pkg/
 
 CMD [ "/app/pkg/start.sh" ]
diff --git a/default_prometheus_variables.sh b/env.sh.template
similarity index 100%
rename from default_prometheus_variables.sh
rename to env.sh.template
diff --git a/start.sh b/start.sh
index 45dfd96..30b6026 100755
--- a/start.sh
+++ b/start.sh
@@ -11,13 +11,15 @@ fi
 
 chown -R cloudron:cloudron /app/data
 
-if [[ ! -f /app/data/prometheus_variables.sh ]]; then
-    echo "=> Copy default prometheus variable file since it does not exist"
-    cp /app/pkg/default_prometheus_variables.sh /app/data/prometheus_variables.sh
+[[ -f /app/data/prometheus_variables.sh ]] && mv /app/data/env.sh
+
+if [[ ! -f /app/data/env.sh ]]; then
+    echo "=> Copy default env.sh"
+    cp /app/pkg/env.sh.template /app/data/env.sh
 fi
 
 echo "=> Source custom variables"
-source /app/data/prometheus_variables.sh
+source /app/data/env.sh
 
 echo "=> Starting Prometheus with retention time of $retention_time"
 exec /usr/local/bin/gosu cloudron:cloudron /app/code/prometheus --config.file=/app/data/config/prometheus.yml --storage.tsdb.path=/app/data/runtime --storage.tsdb.retention.time="${retention_time:-15d}"