diff --git a/containers/zammad/Dockerfile b/containers/zammad/Dockerfile
index c24b219..5a5168c 100644
--- a/containers/zammad/Dockerfile
+++ b/containers/zammad/Dockerfile
@@ -26,34 +26,34 @@ LABEL org.label-schema.build-date="$BUILD_DATE" \
       org.label-schema.docker.cmd="sysctl -w vm.max_map_count=262144;docker-compose up"
 
 # install dependencies & gosu
-RUN BUILD_DEPENDENCIES="build-essential ca-certificates curl dirmngr git gnupg2 libffi-dev libpq5 libpq-dev nginx rsync" \
-    set -ex \
-	  && apt-get update && apt-get install -y --no-install-recommends ${BUILD_DEPENDENCIES} && rm -rf /var/lib/apt/lists/* \
-	  && curl -s -J -L -o /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/${GOSU_VERSION}/gosu-$(dpkg --print-architecture)" \
-	  && curl -s -J -L -o /usr/local/bin/gosu.asc "https://github.com/tianon/gosu/releases/download/${GOSU_VERSION}/gosu-$(dpkg --print-architecture).asc" \
-	  && export GNUPGHOME="$(mktemp -d)" \
-	  && gpg --keyserver ha.pool.sks-keyservers.net --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4 \
-	  && gpg --batch --verify /usr/local/bin/gosu.asc /usr/local/bin/gosu \
-	  && rm -rf "${GNUPGHOME}" /usr/local/bin/gosu.asc \
-	  && chmod +x /usr/local/bin/gosu \
-	  && gosu nobody true
+RUN BUILD_DEPENDENCIES="build-essential ca-certificates curl dirmngr git gnupg2 libffi-dev libpq5 libpq-dev nginx rsync" && \
+  set -ex && \
+  apt-get update && apt-get install -y --no-install-recommends ${BUILD_DEPENDENCIES} && rm -rf /var/lib/apt/lists/* && \
+  curl -s -J -L -o /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/${GOSU_VERSION}/gosu-$(dpkg --print-architecture)" && \
+  curl -s -J -L -o /usr/local/bin/gosu.asc "https://github.com/tianon/gosu/releases/download/${GOSU_VERSION}/gosu-$(dpkg --print-architecture).asc" && \
+  export GNUPGHOME="$(mktemp -d)" && \
+  gpg --no-tty --keyserver ha.pool.sks-keyservers.net --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4 && \
+  gpg --no-tty --batch --verify /usr/local/bin/gosu.asc /usr/local/bin/gosu && \
+  rm -rf "${GNUPGHOME}" /usr/local/bin/gosu.asc && \
+  chmod +x /usr/local/bin/gosu && \
+  gosu nobody true
 
 # install zammad
-RUN groupadd -g 1000 ${ZAMMAD_USER} \
-    && useradd -M -d ${ZAMMAD_DIR} -s /bin/bash -u 1000 -g 1000 ${ZAMMAD_USER} \
-    && cd $(dirname ${ZAMMAD_TMP_DIR}) \
-    && curl -s -J -L -O "${TAR_GZ_URL}" \
-    && tar -xzf zammad-${GIT_BRANCH}.tar.gz \
-    && rm zammad-${GIT_BRANCH}.tar.gz \
-    && cd ${ZAMMAD_TMP_DIR} \
-    && bundle install --without test development mysql \
-    && contrib/packager.io/fetch_locales.rb \
-    && sed -e 's#.*adapter: postgresql#  adapter: nulldb#g' -e 's#.*username:.*#  username: postgres#g' -e 's#.*password:.*#  password: \n  host: zammad-postgresql\n#g' < contrib/packager.io/database.yml.pkgr > config/database.yml \
-    && sed -i '/# Use a different logger for distributed setups./a \ \ config.logger = Logger.new(STDOUT)' config/environments/production.rb \
-    && sed -i 's/.*scheduler_\(err\|out\).log.*//g' script/scheduler.rb \
-    && bundle exec rake assets:precompile \
-    && rm -r tmp/cache \
-    && chown -R ${ZAMMAD_USER}:${ZAMMAD_USER} ${ZAMMAD_TMP_DIR}
+RUN groupadd -g 1000 ${ZAMMAD_USER} && \
+  useradd -M -d ${ZAMMAD_DIR} -s /bin/bash -u 1000 -g 1000 ${ZAMMAD_USER} && \
+  cd $(dirname ${ZAMMAD_TMP_DIR}) && \
+  curl -s -J -L -O "${TAR_GZ_URL}" && \
+  tar -xzf zammad-${GIT_BRANCH}.tar.gz && \
+  rm zammad-${GIT_BRANCH}.tar.gz && \
+  cd ${ZAMMAD_TMP_DIR} && \
+  bundle install --without test development mysql && \
+  contrib/packager.io/fetch_locales.rb && \
+  sed -e 's#.*adapter: postgresql#  adapter: nulldb#g' -e 's#.*username:.*#  username: postgres#g' -e 's#.*password:.*#  password: \n  host: zammad-postgresql\n#g' < contrib/packager.io/database.yml.pkgr > config/database.yml && \
+  sed -i '/# Use a different logger for distributed setups./a \ \ config.logger = Logger.new(STDOUT)' config/environments/production.rb \
+  sed -i 's/.*scheduler_\(err\|out\).log.*//g' script/scheduler.rb && \
+  bundle exec rake assets:precompile && \
+  rm -r tmp/cache && \
+  chown -R ${ZAMMAD_USER}:${ZAMMAD_USER} ${ZAMMAD_TMP_DIR}
 
 # docker init
 COPY containers/zammad/docker-entrypoint.sh /