diff --git a/fluent-package/yum/systemd-test/update-to-next-major-version.sh b/fluent-package/yum/systemd-test/update-to-next-major-version.sh
index b95467806..bf2c31a87 100755
--- a/fluent-package/yum/systemd-test/update-to-next-major-version.sh
+++ b/fluent-package/yum/systemd-test/update-to-next-major-version.sh
@@ -9,8 +9,11 @@ status_before_update=$2 # active / inactive
 
 install_current
 
+sudo systemctl enable fluentd
+
 if [ "$status_before_update" = active ]; then
     sudo systemctl start fluentd
+    main_pid=$(eval $(systemctl show fluentd --property=MainPID) && echo $MainPID)
 fi
 
 # Set FLUENT_PACKAGE_SERVICE_RESTART
@@ -30,13 +33,81 @@ sudo $DNF install -y $package
 # Show bundled ruby version
 /opt/fluent/bin/ruby -v
 
-# Test: Check whether plugin/gem were installed during upgrading
-if [ "$service_restart" != manual ] && [ "$status_before_update" = active ]; then
-    # plugin gem should be installed automatically
-    /opt/fluent/bin/fluent-gem list | grep fluent-plugin-concat
-    # Non fluent-plugin- prefix gem should not be installed automatically
-    (! /opt/fluent/bin/fluent-gem list | grep gqtp)
-else
-    # plugin gem should not be installed automatically
+# Test: The service should take over the state
+systemctl is-enabled fluentd
+
+if [ "$status_before_update" = inactive ]; then
+    # Test: The service should NOT start automatically
+    (! systemctl is-active fluentd)
+    # Test: Plugin gem should not be installed automatically
     (! /opt/fluent/bin/fluent-gem list | grep fluent-plugin-concat)
+else
+    # Test: The process before update should continue to run
+    systemctl is-active fluentd
+    test $main_pid -eq $(eval $(systemctl show fluentd --property=MainPID) && echo $MainPID)
+
+    sleep 15
+
+    if [ "$service_restart" = manual ]; then
+        # Test: Plugin gem should not be installed automatically
+        (! /opt/fluent/bin/fluent-gem list | grep fluent-plugin-concat)
+        # Test: Main process should NOT be replaced until USR2 signal fired
+        test $main_pid  -eq $(eval $(systemctl show fluentd --property=MainPID) && echo $MainPID)
+
+        sudo kill -USR2 $main_pid
+        sleep 15
+
+        # Test: Main process should be replaced by USR2 signal
+        test $main_pid -ne $(eval $(systemctl show fluentd --property=MainPID) && echo $MainPID)
+    else
+        # Test: Plugin gem should be installed automatically
+        /opt/fluent/bin/fluent-gem list | grep fluent-plugin-concat
+        # Test: Non fluent-plugin- prefix gem should not be installed automatically
+        (! /opt/fluent/bin/fluent-gem list | grep gqtp)
+        # Test: Main process should be replaced automatically
+        test $main_pid -ne $(eval $(systemctl show fluentd --property=MainPID) && echo $MainPID)
+    fi
 fi
+
+# Ensure the service is started
+sudo systemctl start fluentd
+
+# Test: migration process from v4 must not be done
+(! test -e /etc/td-agent)
+(! test -e /etc/fluent/td-agent.conf)
+(! test -e /var/log/td-agent)
+(! test -e /var/log/fluent/td-agent.log)
+(! test -h /usr/sbin/td-agent)
+(! test -h /usr/sbin/td-agent-gem)
+
+# Test: environmental variables
+pid=$(eval $(systemctl show fluentd --property=MainPID) && echo $MainPID)
+env_vars=$(sudo sed -e 's/\x0/\n/g' /proc/$pid/environ)
+test $(eval $env_vars && echo $HOME) = "/var/lib/fluent"
+test $(eval $env_vars && echo $LOGNAME) = "fluentd"
+test $(eval $env_vars && echo $USER) = "fluentd"
+test $(eval $env_vars && echo $FLUENT_CONF) = "/etc/fluent/fluentd.conf"
+test $(eval $env_vars && echo $FLUENT_PACKAGE_LOG_FILE) = "/var/log/fluent/fluentd.log"
+test $(eval $env_vars && echo $FLUENT_PLUGIN) = "/etc/fluent/plugin"
+test $(eval $env_vars && echo $FLUENT_SOCKET) = "/var/run/fluent/fluentd.sock"
+
+# Test: logs
+sleep 3
+test -e /var/log/fluent/fluentd.log
+(! grep -e '\[warn\]' -e '\[error\]' -e '\[fatal\]' /var/log/fluent/fluentd.log)
+
+# Uninstall
+sudo $DNF remove -y fluent-package
+sudo systemctl daemon-reload
+
+(! getent passwd td-agent >/dev/null)
+(! getent group td-agent >/dev/null)
+getent passwd fluentd >/dev/null
+getent group fluentd >/dev/null
+
+# `sudo systemctl daemon-reload` clears the service completely.
+#   (The result of `systemctl status` will be `unfound`)
+# Note: RPM does not leave links like `@/etc/systemd/system/fluentd.service`.
+#   (Different from deb)
+
+(! systemctl status --no-pager fluentd)