diff --git a/.github/workflows/apt.yml b/.github/workflows/apt.yml
index df82ce365..c0d2b94ed 100644
--- a/.github/workflows/apt.yml
+++ b/.github/workflows/apt.yml
@@ -229,9 +229,8 @@ jobs:
           - Ubuntu Jammy amd64
           - Ubuntu Noble amd64
         test:
-          - "update-from-v4.sh local"
-          - "update-from-v4.sh v5"
-          - "update-from-v4.sh lts"
+          - "update-from-v4.sh"
+          - "update-from-v4.sh via-v5"
           - "update-from-v5-lts.sh"
           - "downgrade-to-v4.sh"
           - "downgrade-to-v5-lts.sh"
@@ -270,22 +269,18 @@ jobs:
             container-image: images:ubuntu/24.04
         exclude:
           - label: Debian bookworm amd64
-            test: update-from-v4.sh local
+            test: update-from-v4.sh
           - label: Debian bookworm amd64
-            test: update-from-v4.sh v5
-          - label: Debian bookworm amd64
-            test: update-from-v4.sh lts
+            test: update-from-v4.sh via-v5
           - label: Debian bookworm amd64
             test: update-to-next-version-with-backward-compat-for-v4.sh
           - label: Debian bookworm amd64
             test: downgrade-to-v4.sh
           # Temporary disable test for trixie (not released yet)
           - label: Debian trixie amd64
-            test: update-from-v4.sh local
-          - label: Debian trixie amd64
-            test: update-from-v4.sh v5
+            test: update-from-v4.sh
           - label: Debian trixie amd64
-            test: update-from-v4.sh lts
+            test: update-from-v4.sh via-v5
           - label: Debian trixie amd64
             test: update-from-v5-lts.sh
           - label: Debian trixie amd64
@@ -299,11 +294,9 @@ jobs:
           - label: Debian trixie amd64
             test: update-to-next-version-with-backward-compat-for-v4.sh
           - label: Ubuntu Noble amd64
-            test: update-from-v4.sh local
-          - label: Ubuntu Noble amd64
-            test: update-from-v4.sh v5
+            test: update-from-v4.sh
           - label: Ubuntu Noble amd64
-            test: update-from-v4.sh lts
+            test: update-from-v4.sh via-v5
           - label: Ubuntu Noble amd64
             test: update-to-next-version-with-backward-compat-for-v4.sh
           - label: Ubuntu Noble amd64
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index 16bcf6829..1e2d7b133 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -62,6 +62,7 @@ jobs:
         test:
           - "install-test.ps1"
           - "update-from-v4-test.ps1"
+          - "update-from-v4-test.ps1 -ViaV5"
           - "update-from-v5-test.ps1"
           - "serverspec-test.ps1"
     steps:
diff --git a/.github/workflows/yum.yml b/.github/workflows/yum.yml
index 6ae710b5e..db5e7c9fd 100644
--- a/.github/workflows/yum.yml
+++ b/.github/workflows/yum.yml
@@ -285,6 +285,7 @@ jobs:
           - AmazonLinux 2023 x86_64
         test:
           - "update-from-v4.sh"
+          - "update-from-v4.sh via-v5"
           - "update-from-v5-lts.sh"
           - "downgrade-to-v4.sh"
           - "downgrade-to-v5-lts.sh"
@@ -321,6 +322,8 @@ jobs:
         exclude:
           - label: AmazonLinux 2023 x86_64
             test: update-from-v4.sh
+          - label: AmazonLinux 2023 x86_64
+            test: update-from-v4.sh via-v5
           - label: AmazonLinux 2023 x86_64
             test: update-to-next-version-with-backward-compat-for-v4.sh
           - label: AmazonLinux 2023 x86_64
diff --git a/fluent-package/apt/systemd-test/update-from-v4.sh b/fluent-package/apt/systemd-test/update-from-v4.sh
index 00b47d47d..03d6d2994 100755
--- a/fluent-package/apt/systemd-test/update-from-v4.sh
+++ b/fluent-package/apt/systemd-test/update-from-v4.sh
@@ -4,6 +4,8 @@ set -exu
 
 . $(dirname $0)/../commonvar.sh
 
+testcase=${1:-directly}
+
 # Install v4
 sudo apt install -y curl ca-certificates
 curl -fsSL https://toolbelt.treasuredata.com/sh/install-${distribution}-${code_name}-td-agent4.sh | sh
@@ -25,22 +27,15 @@ done
 sudo systemctl stop td-agent
 
 # Install the current
-case $1 in
-  local)
-    sudo apt install -V -y \
-      /host/${distribution}/pool/${code_name}/${channel}/*/*/fluent-package_*_${architecture}.deb \
-      /host/${distribution}/pool/${code_name}/${channel}/*/*/td-agent_*_all.deb 2>&1 | tee upgrade.log
-    # Test: needrestart was suppressed
-    test_suppressed_needrestart upgrade.log
-    ;;
-  v5)
-    curl --fail --silent --show-error --location https://toolbelt.treasuredata.com/sh/install-${distribution}-${code_name}-fluent-package5.sh | sh 2>&1 | tee upgrade.log
-    test_suppressed_needrestart upgrade.log
-    ;;
-  lts)
+if [ "$testcase" = via-v5 ]; then
     curl --fail --silent --show-error --location https://toolbelt.treasuredata.com/sh/install-${distribution}-${code_name}-fluent-package5-lts.sh | sh
-    ;;
-esac
+fi
+sudo apt install -V -y \
+    /host/${distribution}/pool/${code_name}/${channel}/*/*/fluent-package_*_${architecture}.deb \
+    /host/${distribution}/pool/${code_name}/${channel}/*/*/td-agent_*_all.deb 2>&1 | tee upgrade.log
+
+# Test: needrestart was suppressed
+test_suppressed_needrestart upgrade.log
 
 # Test: service status
 systemctl status --no-pager fluentd
diff --git a/fluent-package/msi/update-from-v4-test.ps1 b/fluent-package/msi/update-from-v4-test.ps1
index 1fa41ef4f..7b58cd640 100644
--- a/fluent-package/msi/update-from-v4-test.ps1
+++ b/fluent-package/msi/update-from-v4-test.ps1
@@ -1,3 +1,7 @@
+Param(
+    [switch] $ViaV5 = $false
+)
+
 $ErrorActionPreference = 'Stop'
 $ProgressPreference = 'SilentlyContinue'
 Set-PSDebug -Trace 1
@@ -24,7 +28,11 @@ Add-Content -Path "C:\\opt\\td-agent\\etc\\td-agent\\td-agent.conf" -Encoding UT
 Restart-Service fluentdwinsvc
 Start-Sleep 30 # Must wait until all processes are surely started.
 
-# Update to v5
+# Update to current
+if ($ViaV5) {
+    Invoke-WebRequest "https://s3.amazonaws.com/packages.treasuredata.com/lts/5/windows/fluent-package-5.0.7-x64.msi" -OutFile "fluent-package-5.0.7-x64.msi"
+    Start-Process msiexec -ArgumentList "/i", "fluent-package-5.0.7-x64.msi", "/quiet" -Wait -NoNewWindow
+}
 $new_package = ((Get-Item "C:\\fluentd\\fluent-package\\msi\\repositories\\fluent-package-*.msi") | Sort-Object -Descending { $_.LastWriteTime } | Select-Object -First 1).FullName
 Start-Process msiexec -ArgumentList "/i", $new_package, "/quiet" -Wait -NoNewWindow
 Start-Service fluentdwinsvc
diff --git a/fluent-package/yum/systemd-test/update-from-v4.sh b/fluent-package/yum/systemd-test/update-from-v4.sh
index 8b24053bb..c1a710eb7 100755
--- a/fluent-package/yum/systemd-test/update-from-v4.sh
+++ b/fluent-package/yum/systemd-test/update-from-v4.sh
@@ -4,6 +4,8 @@ set -exu
 
 . $(dirname $0)/common.sh
 
+testcase=${1:-directly}
+
 install_v4
 sudo systemctl enable --now td-agent
 systemctl status --no-pager td-agent
@@ -17,7 +19,12 @@ for d in $(seq 1 10); do
     sudo touch /var/log/td-agent/$d.log
 done
 
+# Install current
+if [ "$testcase" = via-v5 ]; then
+    install_v5_lts
+fi
 install_current
+sleep 3
 
 # Test: take over enabled state
 systemctl is-enabled fluentd