diff --git a/debian/postinst b/debian/postinst
index 063ab90f12..7301dfe8f1 100755
--- a/debian/postinst
+++ b/debian/postinst
@@ -73,8 +73,9 @@ case "$1" in
         mkdir -p /etc/gitlab/ssl
         if [ -f "${nginx_ssl_conf_example_gz}" ]; then
           # undo dh_installdocs auto compress
-	  zcat ${nginx_ssl_conf_example_gz} >/tmp/gitlab-ssl
-	  export nginx_conf_example="/tmp/gitlab-ssl"
+	  export nginx_conf_example_tmp=$(mktemp)
+	  zcat ${nginx_ssl_conf_example_gz} > ${nginx_conf_example_tmp}
+	  export nginx_conf_example=${nginx_conf_example_tmp}
 	fi
 
         # Check if letsencrypt option is selected
@@ -90,10 +91,10 @@ case "$1" in
       if test -f ${nginx_conf_example}; then
         sed -e "s/YOUR_SERVER_FQDN/${GITLAB_HOST}/"\
         ${nginx_conf_example} >/etc/nginx/sites-available/${GITLAB_HOST}
-        ln -fs /etc/nginx/sites-available/${RET} /etc/nginx/sites-enabled/
-        rm -f /tmp/gitlab-ssl
+        ln -fs /etc/nginx/sites-available/${GITLAB_HOST} /etc/nginx/sites-enabled/
+        rm -f ${nginx_conf_example_tmp}
       else
-        echo "nginx.conf.example not found"
+        echo "nginx example configuration file not found"
         exit 1
       fi
     else