diff --git a/fluent-package/templates/package-scripts/fluent-package/deb/postinst b/fluent-package/templates/package-scripts/fluent-package/deb/postinst
index 9e012b20..77bb10eb 100755
--- a/fluent-package/templates/package-scripts/fluent-package/deb/postinst
+++ b/fluent-package/templates/package-scripts/fluent-package/deb/postinst
@@ -145,37 +145,43 @@ migration_from_v4_post_process() {
     fi
 }
 
-local_plugin_migration=/tmp/<%= package_dir %>/.local_plugin_migration
-local_base_plugins=/tmp/<%= package_dir %>/.local_base_plugins
-local_missing_plugins=/tmp/<%= package_dir %>/.local_missing_plugins
+local_base_gems=/tmp/<%= package_dir %>/.local_base_gems
+local_current_gems=/tmp/<%= package_dir %>/.local_current_gems
+local_missing_gems=/tmp/<%= package_dir %>/.local_missing_gems
 install_missing_plugins() {
-    if [ -f $local_plugin_migration ]; then
-        echo "Checking network connectivity..."
-	if ! curl --fail --silent -O https://rubygems.org/specs.4.8.gz; then
-	    echo "Can't install missing plugins automatically, please install the following plugins manually."
-	    cat $local_plugin_migration
-	else
-	    echo "Install missing plugins automatically..."
-	    /usr/sbin/fluent-gem list | grep fluent-plugin | cut -d' ' -f1 > $local_base_plugins
-	    # NOTE: Do not install already bundled plugins
-	    diff -u $local_base_plugins $local_plugin_migration | grep '^+fluent' | sed -e 's/\+//' > $local_missing_plugins
-	    if [ -s $local_missing_plugins ]; then
-		cat $local_missing_plugins | xargs sudo /usr/sbin/fluent-gem install --no-document
-	    else
-		echo "No need to install missing plugins..."
+    # Install missing gems (even though systemd is not available, it works)
+    mkdir -p /tmp/<%= package_dir %>
+    /usr/sbin/fluent-gem list | cut -d' ' -f1 > $local_current_gems
+    if ! curl --fail --silent -O https://rubygems.org/specs.4.8.gz; then
+	echo "No network connectivity..."
+    else
+	if [ -f $local_base_gems ]; then
+	    # mark '-' as missing gems
+	    # NOTE: possibility to install gems which is deprecated or not needed anymore.
+	    diff -u $local_base_gems $local_current_gems | sed -e '1,2d' | grep '^-' | sed -e 's/^-//g' > $local_missing_gems
+	    if [ -s $local_missing_gems ]; then
+		echo "Try to install the following gems:"
+		cat $local_missing_gems
+		while read gem
+		do
+		    if ! /usr/sbin/fluent-gem install --no-document $gem; then
+			echo "Can't install missing gem automatically: please install $gem manually."
+		    fi
+		done < $local_missing_gems
 	    fi
-	    rm -f $local_base_plugins
-	    rm -f $local_missing_plugins
+	else
+	    echo "No need to install missing gems..."
 	fi
-	rm -f $local_plugin_migration
+	rm -f $local_base_gems
     fi
+    rm -f $local_current_gems
 }
 
 fluentd_auto_restart() {
     if [ -d /run/systemd/system ]; then
 	pid=$(systemctl show <%= service_name %> --property=MainPID --value)
 	if [ $pid -ne 0 ]; then
-	    env_vars=$(sudo sed -e 's/\x0/\n/g' /proc/$pid/environ)
+	    env_vars=$(sed -e 's/\x0/\n/g' /proc/$pid/environ)
 	    action=$(eval $env_vars && echo $FLUENT_PACKAGE_SERVICE_RESTART)
 	    case "$action" in
 		auto)
diff --git a/fluent-package/templates/package-scripts/fluent-package/deb/preinst b/fluent-package/templates/package-scripts/fluent-package/deb/preinst
index 9a039afa..57b03462 100755
--- a/fluent-package/templates/package-scripts/fluent-package/deb/preinst
+++ b/fluent-package/templates/package-scripts/fluent-package/deb/preinst
@@ -10,17 +10,11 @@ set -e
 # for details, see https://www.debian.org/doc/debian-policy/ or
 # the debian-policy package.
 
-local_plugin_migration=/tmp/<%= package_dir %>/.local_plugin_migration
+local_base_gems=/tmp/<%= package_dir %>/.local_base_gems
 migrate_local_plugins() {
-    # collect manually installed plugins
-    archive_path=$(sudo /opt/fluent/bin/fluent-diagtool -t fluentd -o /tmp | tail -n 1 | cut -d' ' -f10)
-    local_gem_output=$(echo $archive_path | sed -e 's/diagout-//' -e 's/.tar.gz//')/output/gem_local_list.output
-    if [ -f $local_gem_output ]; then
-        if [ -s $local_gem_output ]; then
-	    # If there are missing plugins, mark path to it
-	    cp $local_gem_output $local_plugin_migration
-	fi
-    fi
+    # collect list of gems
+    # fluent-diagtool depends on systemd, piuparts fails
+    /opt/fluent/bin/fluent-gem list | cut -d' ' -f1 > $local_base_gems
 }
 
 case "$1" in
diff --git a/fluent-package/yum/fluent-package.spec.in b/fluent-package/yum/fluent-package.spec.in
index 0617bbe4..f83cb4ca 100644
--- a/fluent-package/yum/fluent-package.spec.in
+++ b/fluent-package/yum/fluent-package.spec.in
@@ -32,8 +32,9 @@
 %define v4migration_with_restart /tmp/@PACKAGE_DIR@/.v4migration_with_restart
 %define v4migration_old_rotate_config_saved /tmp/@PACKAGE_DIR@/.old_rotate_config
 %define v4migration_enabled_service /tmp/@PACKAGE_DIR@/.v4migration_enabled_service
-%define local_plugin_migration /tmp/@PACKAGE_DIR@/.local_plugin_migration
-%define local_base_plugins /tmp/@PACKAGE_DIR@/.base-plugins
+%define local_base_gems /tmp/@PACKAGE_DIR@/.local_base_gems
+%define local_current_gems /tmp/@PACKAGE_DIR@/.local_current_gems
+%define local_missing_gems /tmp/@PACKAGE_DIR@/.local_missing_gems
 
 # Omit the brp-python-bytecompile automagic because post hook for ffi fails on AmazonLinux 2.
 %if %{_amazon_ver} == 2
@@ -189,23 +190,8 @@ else
     fi
 fi
 if [ $1 -eq 2 ]; then
-  # collect manually installed plugins during upgrading
-  archive_path=$(sudo /opt/fluent/bin/fluent-diagtool -t fluentd -o /tmp  | tail -n 1 | cut -d' ' -f10)
-  local_gem_output=$(echo $archive_path | sed -e 's/diagout-//' -e 's/.tar.gz//')/output/gem_local_list.output
-  if [ -f $local_gem_output ]; then
-      if [ -s $local_gem_output ]; then
-	  # If there are missing plugins, mark path to it
-	  echo "Detected missing plugins..."
-	  cp $local_gem_output %{local_plugin_migration}
-      else
-	  echo "Missing $local_gem_output"
-      fi
-  else
-      echo "Missing $local_gem_output to check locally installed plugins."
-  fi
-  rm -f $archive_path
-  archive_dir=$(echo $archive_path | sed -e 's/diagout-//' -e 's/.tar.gz//')
-  rm -rf $archive_dir
+  # collect installed gems during upgrading
+  /opt/fluent/bin/fluent-gem list | cut -d' ' -f1 > %{local_base_gems}
 fi
 
 %preun
@@ -324,27 +310,27 @@ if [ -f "%{_sysconfdir}/prelink.conf" ]; then
 fi
 if [ $1 -eq 2 ]; then
   # install missing plugins during upgrading package
-  if [ -f %{local_plugin_migration} ]; then
-    echo "Checking network connectivity..."
-    curl --fail --silent -O https://rubygems.org/specs.4.8.gz
-    if [ $? -eq 0 ]; then
-      echo "Install missing plugins automatically..."
-      /usr/sbin/fluent-gem list | grep fluent-plugin | cut -d' ' -f1 > %{local_base_plugins}
-      # NOTE: Do not install already bundled plugins
-      diff -u %{local_base_plugins} %{local_plugin_migration} | grep '^+fluent' | sed -e 's/\+//' > %{local_missing_plugins}
-      if [ -s %{local_missing_plugins} ]; then
-        cat %{local_missing_plugins} | xargs sudo /usr/sbin/fluent-gem install --no-document
+  /usr/sbin/fluent-gem list | cut -d' ' -f1 > %{local_current_gems}
+  if [ -f %{local_base_gems} ]; then
+    diff -u %{local_base_gems} %{local_current_gems} | grep '^-' | sed -e 's/^-//g' > %{local_missing_gems}
+    if [ -s %{local_missing_gems} ]; then
+      echo "Try to install the following gems:"
+      cat %{local_missing_gems}
+      if ! curl --fail --silent -O https://rubygems.org/specs.4.8.gz; then
+	echo "No network connectivity..."
       else
-         echo "No need to install missing plugins..."
+	echo "Install missing dependency gems..."
+	while read gem
+	do
+          if ! /usr/sbin/fluent-gem install --no-document $gem; then
+	    echo "Can't install missing gem automatically, please install $gem manually."
+          fi
+	done < %{local_missing_gems}
       fi
-      rm -f %{local_base_plugins}
-      rm -f %{local_missing_plugins}
-    else
-      echo "Can't install missing plugins automatically, please install the following plugins manually."
-      cat %{local_plugin_migration}
     fi
-    rm -f %{local_plugin_migration}
+    rm -f %{local_missing_gems}
   fi
+  rm -f %{local_current_gems}
 fi
 
 %postun