diff --git a/Dockerfile b/Dockerfile
index 9e40ad1ddaac34298b0b0c708daa05805b0f5577..d285ff2435f38f0d6c0b0e8383542b3814a59182 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,14 +1,10 @@
 FROM bitnami/phpbb:3.3.8
 MAINTAINER Andrej Ramašeuski <andrej.ramaseuski@pirati.cz>
 
-RUN set -ex; \
-        mkdir -p /var/lib/apt/lists/partial /var/lib/apt/lists/auxfiles /var/lib/apt/mirrors/partial  /var/lib/apt/mirrors/periodic && \
-        apt-get update && \
-        DEBIAN_FRONTEND=noninteractive \
-        apt-get install --no-install-recommends -y \
-        \
-        cron
-
+USER 0
+RUN install_packages cron
 COPY crontab /etc/cron.d/
+USER 1001
+
 COPY phpbb /opt/bitnami/phpbb
 CMD [  ( cron -f -l 8 & ) & "/opt/bitnami/scripts/apache/run.sh" ]