diff --git a/Gemfile b/Gemfile
index ace63c42f..219d3e698 100644
--- a/Gemfile
+++ b/Gemfile
@@ -31,15 +31,8 @@ gem "devise"
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem "byebug", platforms: %i[mri mingw x64_mingw]
-  gem "capybara", require: false
   gem "dotenv-rails"
-  gem "factory_bot_rails"
   gem "pry-byebug"
-  gem "selenium-webdriver", require: false
-  gem "simplecov", require: false
-  %w[rspec-core rspec-expectations rspec-mocks rspec-rails rspec-support].each do |lib|
-    gem lib, git: "https://github.com/rspec/#{lib}.git", branch: "main", require: false
-  end
 end
 
 group :development do
@@ -56,5 +49,16 @@ group :development do
   gem "scss_lint-govuk"
 end
 
+group :test do
+  gem "capybara", require: false
+  gem "factory_bot_rails"
+  gem "selenium-webdriver", require: false
+  gem "simplecov", require: false
+  gem "database_cleaner-active_record", require: false
+  %w[rspec-core rspec-expectations rspec-mocks rspec-rails rspec-support].each do |lib|
+    gem lib, git: "https://github.com/rspec/#{lib}.git", branch: "main", require: false
+  end
+end
+
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem "tzinfo-data", platforms: %i[mingw mswin x64_mingw jruby]
diff --git a/Gemfile.lock b/Gemfile.lock
index 6ec00c5e5..8aeda17e0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -140,6 +140,10 @@ GEM
     coderay (1.1.3)
     concurrent-ruby (1.1.9)
     crass (1.0.6)
+    database_cleaner-active_record (2.0.1)
+      activerecord (>= 5.a)
+      database_cleaner-core (~> 2.0.0)
+    database_cleaner-core (2.0.1)
     deep_merge (1.2.1)
     devise (4.8.0)
       bcrypt (~> 3.0)
@@ -390,6 +394,7 @@ DEPENDENCIES
   bootsnap (>= 1.4.4)
   byebug
   capybara
+  database_cleaner-active_record
   devise
   discard
   dotenv-rails
diff --git a/spec/factories/case_log.rb b/spec/factories/case_log.rb
index 86472e264..044a4cbac 100644
--- a/spec/factories/case_log.rb
+++ b/spec/factories/case_log.rb
@@ -1,6 +1,6 @@
 FactoryBot.define do
   factory :case_log do
-    id { (CaseLog.maximum(:id) || 0) + 1 }
+    sequence(:id) { |i| i }
     trait :in_progress do
       status { 1 }
       tenant_code { "TH356" }
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index 726c09017..b873a5929 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -6,6 +6,7 @@ require File.expand_path("../config/environment", __dir__)
 abort("The Rails environment is running in production mode!") if Rails.env.production?
 require "rspec/rails"
 require "capybara/rspec"
+require 'database_cleaner/active_record'
 
 # Comment to run `js: true specs` with visible browser interaction
 Capybara.javascript_driver = :selenium_headless
@@ -42,7 +43,48 @@ RSpec.configure do |config|
   # If you're not using ActiveRecord, or you'd prefer not to run each of your
   # examples within a transaction, remove the following line or assign false
   # instead of true.
-  config.use_transactional_fixtures = true
+  # config.use_transactional_fixtures = true
+
+  config.before(:suite) do
+    if config.use_transactional_fixtures?
+      raise(<<-MSG)
+        Delete line `config.use_transactional_fixtures = true` from rails_helper.rb
+        (or set it to false) to prevent uncommitted transactions being used in
+        JavaScript-dependent specs.
+
+        During testing, the app-under-test that the browser driver connects to
+        uses a different database connection to the database connection used by
+        the spec. The app's database connection would not be able to access
+        uncommitted transaction data setup over the spec's database connection.
+      MSG
+    end
+    DatabaseCleaner.clean_with(:truncation)
+  end
+
+  config.before(:each) do
+    DatabaseCleaner.strategy = :transaction
+  end
+
+  config.before(:each, type: :feature) do
+    # :rack_test driver's Rack app under test shares database connection
+    # with the specs, so continue to use transaction strategy for speed.
+    driver_shares_db_connection_with_specs = Capybara.current_driver == :rack_test
+
+    unless driver_shares_db_connection_with_specs
+      # Driver is probably for an external browser with an app
+      # under test that does *not* share a database connection with the
+      # specs, so use truncation strategy.
+      DatabaseCleaner.strategy = :truncation
+    end
+  end
+
+  config.before(:each) do
+    DatabaseCleaner.start
+  end
+
+  config.append_after(:each) do
+    DatabaseCleaner.clean
+  end
 
   # You can uncomment this line to turn off ActiveRecord support entirely.
   # config.use_active_record = false