diff --git a/2-install-guacamole.sh b/2-install-guacamole.sh
index a737514..d070eaf 100644
--- a/2-install-guacamole.sh
+++ b/2-install-guacamole.sh
@@ -78,7 +78,7 @@ if [ $? -ne 0 ]; then
 else
     echo -e "${LGREEN}OK${GREY}"
 fi
-service postfix restart
+systemctl restart postfix
 
 # Download Guacamole Server
 echo
@@ -330,7 +330,7 @@ fi
 
 # Restart Tomcat
 echo -e "${GREY}Restarting Tomcat service & enable at boot..."
-service ${TOMCAT_VERSION} restart
+systemctl restart ${TOMCAT_VERSION}
 if [ $? -ne 0 ]; then
     echo -e "${LRED}Failed${GREY}" 1>&2
     exit 1
@@ -349,7 +349,7 @@ if [ "${INSTALL_MYSQL}" = true ]; then
     echo -e "${GREY}Restarting MySQL service & enable at boot..."
     # Set MySQl to start at boot
     systemctl enable mysql
-    service mysql restart
+    systemctl restart mysql
     if [ $? -ne 0 ]; then
         echo -e "${LRED}Failed${GREY}" 1>&2
         exit 1
@@ -390,7 +390,7 @@ else
         mysql_tzinfo_to_sql /usr/share/zoneinfo 2>/dev/null | mysql -u root -D mysql -h ${MYSQL_HOST} -P ${MYSQL_PORT}
         crudini --set ${mysqlconfig} mysqld default_time_zone "${timezone}"
         # Restart to apply
-        service mysql restart
+        systemctl restart mysql
     fi
 fi
 if [ $? -ne 0 ]; then
@@ -481,8 +481,8 @@ fi
 # Ensure guacd is started
 echo -e "${GREY}Starting guacd service & enable at boot..."
 systemctl enable guacd
-service guacd stop 2>/dev/null
-service guacd start
+systemctl stop guacd 2>/dev/null
+systemctl start guacd
 if [ $? -ne 0 ]; then
     echo -e "${LRED}Failed. See ${LOG_LOCATION}${GREY}" 1>&2
     exit 1
@@ -539,10 +539,10 @@ fi
 
 if [ "${CHANGE_ROOT}" = true ]; then
 echo -e "${GREY}Setting default Guacamole url to http root...${DGREY}"
-sudo systemctl stop ${TOMCAT_VERSION}
-sudo rm -rf /var/lib/${TOMCAT_VERSION}/webapps/ROOT
-sudo mv /var/lib/${TOMCAT_VERSION}/webapps/guacamole.war /var/lib/${TOMCAT_VERSION}/webapps/ROOT.war
-sudo systemctl start ${TOMCAT_VERSION}
+systemctl stop ${TOMCAT_VERSION}
+rm -rf /var/lib/${TOMCAT_VERSION}/webapps/ROOT
+mv /var/lib/${TOMCAT_VERSION}/webapps/guacamole.war /var/lib/${TOMCAT_VERSION}/webapps/ROOT.war
+systemctl start ${TOMCAT_VERSION}
     if [ $? -ne 0 ]; then
         echo -e "${LRED}Failed. See ${LOG_LOCATION}${GREY}" 1>&2
         exit 1
diff --git a/4b-install-ssl-letsencrypt-nginx.sh b/4b-install-ssl-letsencrypt-nginx.sh
index e0013de..cebfbe8 100644
--- a/4b-install-ssl-letsencrypt-nginx.sh
+++ b/4b-install-ssl-letsencrypt-nginx.sh
@@ -151,7 +151,7 @@ sed -i '/# certbot renew/d' cron_1
 # Randomly choose a daily update schedule and append this to the cron schedule
 HOUR=$(shuf -i 0-23 -n 1)
 MINUTE=$(shuf -i 0-59 -n 1)
-echo "${MINUTE} ${HOUR} * * * /usr/bin/certbot renew --quiet --pre-hook 'service nginx stop' --post-hook 'service nginx start'" >>cron_1
+echo "${MINUTE} ${HOUR} * * * /usr/bin/certbot renew --quiet --pre-hook 'systemctl stop nginx' --post-hook 'systemctl start nginx'" >>cron_1
 # Overwrite old cron settings and cleanup
 crontab cron_1
 rm cron_1
diff --git a/add-smtp-relay-o365.sh b/add-smtp-relay-o365.sh
index 171f7d6..185d12f 100644
--- a/add-smtp-relay-o365.sh
+++ b/add-smtp-relay-o365.sh
@@ -108,7 +108,7 @@ sudo postmap /etc/postfix/generic
 
 # Restart and test
 echo -e "${GREY}Restarting Postfix..."
-sudo service postfix restart
+sudo systemctl restart postfix
 if [ $? -ne 0 ]; then
     echo -e "${LRED}Postfix restart failed. ${GREY}" 1>&2
     exit 1