diff --git a/Dockerfile b/Dockerfile
index 645f442..52cfff6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,10 +1,9 @@
 FROM ubuntu:20.04
 
 # install and configure munin
-# hadolint ignore=DL3008
+ARG DEBIAN_FRONTEND=noninteractive# hadolint ignore=DL3008
 RUN apt-get update -qq \
-    DEBIAN_FRONTEND=noninteractive \
-    apt-get install -y -qq cron munin nginx apache2 wget libapache2-mod-fcgid libcgi-fast-perl ssmtp mailutils curl tzdata autoconf --no-install-recommends \
+    && apt-get install -y -qq cron munin nginx apache2 wget libapache2-mod-fcgid libcgi-fast-perl ssmtp mailutils curl tzdata autoconf --no-install-recommends \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*