diff --git a/fluent-package/apt/systemd-test/downgrade-to-v4.sh b/fluent-package/apt/systemd-test/downgrade-to-v4.sh
index b950ba9df..57a94aded 100755
--- a/fluent-package/apt/systemd-test/downgrade-to-v4.sh
+++ b/fluent-package/apt/systemd-test/downgrade-to-v4.sh
@@ -45,6 +45,11 @@ sudo chown td-agent:td-agent /etc/td-agent
 sudo mv /etc/fluent/td-agent.conf /etc/td-agent/
 curl -fsSL https://toolbelt.treasuredata.com/sh/install-${distribution}-${code_name}-td-agent4.sh | sh
 
+# Show .service
+ls -la /etc/systemd/system
+ls -la /usr/lib/systemd/system/ |grep -E 'td-agent|fluent-package'
+ls -la /usr/lib/systemd/system/multi-user.target.wants/
+
 # Test: service status
 (! systemctl status --no-pager fluentd)
 (systemctl status --no-pager td-agent)