diff --git a/app/lib/vacuum/ng_histories_vacuum.rb b/app/lib/vacuum/ng_histories_vacuum.rb
index 204e6de23fa0e6..f70558f1160085 100644
--- a/app/lib/vacuum/ng_histories_vacuum.rb
+++ b/app/lib/vacuum/ng_histories_vacuum.rb
@@ -12,6 +12,7 @@ def perform
   private
 
   def vacuum_histories!
+    NgwordHistory.where('created_at < ?', HISTORY_LIFE_DURATION.ago).in_batches.destroy_all
     NgRuleHistory.where('created_at < ?', HISTORY_LIFE_DURATION.ago).in_batches.destroy_all
   end
 end
diff --git a/db/migrate/20240227222450_index_to_sort_for_ng_word_created_date.rb b/db/migrate/20240227222450_index_to_sort_for_ng_word_created_date.rb
new file mode 100644
index 00000000000000..672eb3c8a796a8
--- /dev/null
+++ b/db/migrate/20240227222450_index_to_sort_for_ng_word_created_date.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class IndexToSortForNgWordCreatedDate < ActiveRecord::Migration[7.1]
+  disable_ddl_transaction!
+
+  def change
+    add_index :ngword_histories, :created_at, algorithm: :concurrently
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index aeb81e046ecfee..88760ee1eaaa0f 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_02_27_033337) do
+ActiveRecord::Schema[7.1].define(version: 2024_02_27_222450) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -936,6 +936,7 @@
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.integer "count", default: 0, null: false
+    t.index ["created_at"], name: "index_ngword_histories_on_created_at"
     t.index ["uri", "keyword", "created_at"], name: "index_ngword_histories_on_uri_and_keyword_and_created_at"
     t.index ["uri", "reason", "created_at"], name: "index_ngword_histories_on_uri_and_reason_and_created_at"
   end
diff --git a/spec/fabricators/ngword_history_fabricator.rb b/spec/fabricators/ngword_history_fabricator.rb
new file mode 100644
index 00000000000000..35d3b02669de65
--- /dev/null
+++ b/spec/fabricators/ngword_history_fabricator.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+Fabricator(:ngword_history) do
+  uri 'https://test.com/'
+  target_type 0
+  reason 0
+  text 'this is an invalid text'
+  keyword 'invalid'
+end
diff --git a/spec/lib/vacuum/ng_histories_vacuum_spec.rb b/spec/lib/vacuum/ng_histories_vacuum_spec.rb
index d75d7f353b3dad..31f10f1ffd5b40 100644
--- a/spec/lib/vacuum/ng_histories_vacuum_spec.rb
+++ b/spec/lib/vacuum/ng_histories_vacuum_spec.rb
@@ -6,6 +6,8 @@
   subject { described_class.new }
 
   describe '#perform' do
+    let!(:word_history_old) { Fabricate(:ngword_history, created_at: 30.days.ago) }
+    let!(:word_history_recent) { Fabricate(:ngword_history, created_at: 2.days.ago) }
     let!(:rule_history_old) { Fabricate(:ng_rule_history, created_at: 30.days.ago) }
     let!(:rule_history_recent) { Fabricate(:ng_rule_history, created_at: 2.days.ago) }
 
@@ -14,10 +16,12 @@
     end
 
     it 'deletes old history' do
+      expect { word_history_old.reload }.to raise_error ActiveRecord::RecordNotFound
       expect { rule_history_old.reload }.to raise_error ActiveRecord::RecordNotFound
     end
 
     it 'does not delete recent history' do
+      expect { word_history_recent.reload }.to_not raise_error
       expect { rule_history_recent.reload }.to_not raise_error
     end
   end