diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f2f1f334..58bdd30c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,7 +24,7 @@ jobs:
             database-password: 'root'
             database-port: '3306'
             docker-compose-file: 'docker-compose.ci.mysql.yml'
-          - ruby-version: 'jruby-9.4.2.0'
+          - ruby-version: 'jruby-9.3.10.0'
             database-adapter: 'mariadb'
             database-user: 'root'
             database-password: 'root'
@@ -36,7 +36,7 @@ jobs:
             database-password: 'postgres'
             database-port: '5432'
             docker-compose-file: 'docker-compose.ci.postgresql.yml'
-          - ruby-version: 'jruby-9.4.2.0'
+          - ruby-version: 'jruby-9.3.10.0'
             database-adapter: 'postgresql'
             database-user: 'postgres'
             database-password: 'postgres'
diff --git a/.github/workflows/rubocop.yml b/.github/workflows/rubocop.yml
index 0cb5b3c2..7ad39cbe 100644
--- a/.github/workflows/rubocop.yml
+++ b/.github/workflows/rubocop.yml
@@ -10,7 +10,7 @@ jobs:
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 3.2.2
+        ruby-version: 2.6.10
     - name: Install gems
       run: |
         bundle config path vendor/bundle
diff --git a/.rubocop.yml b/.rubocop.yml
index 2dfa4591..0d620c16 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -51,3 +51,9 @@ Style/Documentation:
 
 Style/EmptyElse:
   EnforcedStyle: empty
+
+Style/HashSyntax:
+  Enabled: false
+
+Style/ExplicitBlockArgument:
+  Enabled: false
diff --git a/Gemfile b/Gemfile
index 4c78d1cc..800efdb2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 source 'https://rubygems.org'
-ruby '>= 3.1.0'
+ruby '>= 2.6.0'
 
 gemspec
 
@@ -18,7 +18,7 @@ group :development do
   gem 'simplecov'
 
   if defined?(JRUBY_VERSION)
-    git 'https://github.com/jruby/activerecord-jdbc-adapter', branch: 'master' do
+    git 'https://github.com/jruby/activerecord-jdbc-adapter', branch: 'v61.2' do
       gem 'activerecord-jdbc-adapter'
       # Add the drivers
       gem 'jdbc-mariadb'
@@ -40,4 +40,4 @@ gem 'killbill-client', git: 'https://github.com/killbill/killbill-client-ruby.gi
 # gem 'killbill-client', '3.2.0'
 
 # gem 'kenui', :path => '../killbill-email-notifications-ui'
-gem 'kenui', git: 'https://github.com/killbill/killbill-email-notifications-ui.git', branch: 'master'
+# gem 'kenui', git: 'https://github.com/killbill/killbill-email-notifications-ui.git', branch: 'master'
diff --git a/app/controllers/kaui/accounts_controller.rb b/app/controllers/kaui/accounts_controller.rb
index d0583385..2964215d 100644
--- a/app/controllers/kaui/accounts_controller.rb
+++ b/app/controllers/kaui/accounts_controller.rb
@@ -202,7 +202,7 @@ def trigger_invoice
         render template: 'kaui/invoices/show'
       else
         # Redirect to fetch payments, etc.
-        redirect_to invoice_path(invoice.invoice_id, account_id:), notice: "Generated invoice #{invoice.invoice_number} for target date #{invoice.target_date}"
+        redirect_to invoice_path(invoice.invoice_id, account_id: account_id), notice: "Generated invoice #{invoice.invoice_number} for target date #{invoice.target_date}"
       end
     end
 
diff --git a/app/controllers/kaui/admin_tenants_controller.rb b/app/controllers/kaui/admin_tenants_controller.rb
index 4546f160..eb43e36e 100644
--- a/app/controllers/kaui/admin_tenants_controller.rb
+++ b/app/controllers/kaui/admin_tenants_controller.rb
@@ -448,10 +448,10 @@ def catalog_by_effective_date
 
           catalog << { version_date: data[:version_date],
                        currencies: data[:currencies],
-                       plans: }
+                       plans: plans }
         end
 
-        { catalog: }
+        { catalog: catalog }
       end
     end
 
diff --git a/app/controllers/kaui/audit_logs_controller.rb b/app/controllers/kaui/audit_logs_controller.rb
index 69bf5d83..6ca4b7d8 100644
--- a/app/controllers/kaui/audit_logs_controller.rb
+++ b/app/controllers/kaui/audit_logs_controller.rb
@@ -104,7 +104,7 @@ def history
           error = e.message
         end
 
-        { audits: audit_logs_with_history, error: }
+        { audits: audit_logs_with_history, error: error }
       end
     end
 
diff --git a/app/controllers/kaui/charges_controller.rb b/app/controllers/kaui/charges_controller.rb
index d986fa3e..41573900 100644
--- a/app/controllers/kaui/charges_controller.rb
+++ b/app/controllers/kaui/charges_controller.rb
@@ -15,7 +15,7 @@ def new
         currency = params[:currency] || 'USD'
       end
 
-      @charge = Kaui::InvoiceItem.new(account_id: params.require(:account_id), invoice_id:, amount:, currency:)
+      @charge = Kaui::InvoiceItem.new(account_id: params.require(:account_id), invoice_id: invoice_id, amount: amount, currency: currency)
     end
 
     def create
diff --git a/app/controllers/kaui/credits_controller.rb b/app/controllers/kaui/credits_controller.rb
index 5786b125..53f77ba5 100644
--- a/app/controllers/kaui/credits_controller.rb
+++ b/app/controllers/kaui/credits_controller.rb
@@ -15,7 +15,7 @@ def new
         currency = params[:currency] || 'USD'
       end
 
-      @credit = Kaui::Credit.new(account_id: params.require(:account_id), invoice_id:, amount:, currency:)
+      @credit = Kaui::Credit.new(account_id: params.require(:account_id), invoice_id: invoice_id, amount: amount, currency: currency)
     end
 
     def create
diff --git a/app/controllers/kaui/engine_controller_util.rb b/app/controllers/kaui/engine_controller_util.rb
index eecc9eda..cc4f4503 100644
--- a/app/controllers/kaui/engine_controller_util.rb
+++ b/app/controllers/kaui/engine_controller_util.rb
@@ -53,15 +53,17 @@ def paginate(searcher, data_extractor, formatter)
       pages.each { |page| json[:data] << formatter.call(page) }
 
       respond_to do |format|
-        format.json { render json: }
+        format.json { render json: json }
       end
     end
 
-    def promise(&)
+    def promise
       # Evaluation starts immediately
       ::Concurrent::Promises.future do
         # https://github.com/rails/rails/issues/26847
-        Rails.application.executor.wrap(&)
+        Rails.application.executor.wrap do
+          yield
+        end
       end
     end
 
diff --git a/app/controllers/kaui/home_controller.rb b/app/controllers/kaui/home_controller.rb
index 13499a01..7c54e9af 100644
--- a/app/controllers/kaui/home_controller.rb
+++ b/app/controllers/kaui/home_controller.rb
@@ -46,7 +46,7 @@ def account_search(search_query, search_by = nil, fast = 0, options = {})
         elsif true?(fast)
           redirect_to account_path(account.account_id) and return
         else
-          redirect_to accounts_path(q: search_query, fast:) and return
+          redirect_to accounts_path(q: search_query, fast: fast) and return
         end
       end
     end
@@ -73,7 +73,7 @@ def invoice_search(search_query, search_by = nil, fast = 0, options = {})
         elsif true?(fast)
           redirect_to account_invoice_path(invoice.account_id, invoice.invoice_id) and return
         else
-          redirect_to account_invoices_path(account_id: invoice.account_id, q: search_query, fast:) and return
+          redirect_to account_invoices_path(account_id: invoice.account_id, q: search_query, fast: fast) and return
         end
       end
     end
@@ -100,7 +100,7 @@ def payment_search(search_query, search_by = nil, fast = 0, options = {})
         elsif true?(fast)
           redirect_to account_payment_path(payment.account_id, payment.payment_id) and return
         else
-          redirect_to account_payments_path(account_id: payment.account_id, q: search_query, fast:) and return
+          redirect_to account_payments_path(account_id: payment.account_id, q: search_query, fast: fast) and return
         end
       end
     end
@@ -167,7 +167,7 @@ def custom_field_search(search_query, search_by = nil, fast = 0, options = {})
         if custom_field.blank?
           search_error("No custom field matches \"#{search_query}\"")
         else
-          redirect_to custom_fields_path(q: search_query, fast:)
+          redirect_to custom_fields_path(q: search_query, fast: fast)
         end
       else
         unsupported_external_key_search('CUSTOM FIELD')
@@ -206,7 +206,7 @@ def tag_search(search_query, search_by = nil, fast = 0, options = {})
         if tag.blank?
           search_error("No tag matches \"#{search_query}\"")
         else
-          redirect_to tags_path(q: search_query, fast:)
+          redirect_to tags_path(q: search_query, fast: fast)
         end
       else
         unsupported_external_key_search('TAG')
@@ -217,7 +217,7 @@ def tag_definition_search(search_query, search_by = nil, fast = 0, options = {})
       if search_by == 'ID'
         begin
           Kaui::TagDefinition.find_by_id(search_query, 'NONE', options)
-          redirect_to tag_definitions_path(q: search_query, fast:)
+          redirect_to tag_definitions_path(q: search_query, fast: fast)
         rescue KillBillClient::API::NotFound => _e
           search_error("No tag definition matches \"#{search_query}\"")
         end
@@ -228,12 +228,12 @@ def tag_definition_search(search_query, search_by = nil, fast = 0, options = {})
         if tag_definition.blank?
           begin
             Kaui::TagDefinition.find_by_id(search_query, 'NONE', options)
-            redirect_to tag_definitions_path(q: search_query, fast:) and return
+            redirect_to tag_definitions_path(q: search_query, fast: fast) and return
           rescue KillBillClient::API::NotFound => _e
             search_error("No tag definition matches \"#{search_query}\"")
           end
         else
-          redirect_to tag_definitions_path(q: search_query, fast:)
+          redirect_to tag_definitions_path(q: search_query, fast: fast)
         end
       end
     end
diff --git a/app/controllers/kaui/invoice_tags_controller.rb b/app/controllers/kaui/invoice_tags_controller.rb
index 6088ab27..ac516c45 100644
--- a/app/controllers/kaui/invoice_tags_controller.rb
+++ b/app/controllers/kaui/invoice_tags_controller.rb
@@ -26,7 +26,7 @@ def update
       end
 
       Kaui::Tag.set_for_invoice(invoice_id, tags, current_user.kb_username, params[:reason], params[:comment], options_for_klient)
-      redirect_to kaui_engine.invoice_path(invoice_id, account_id:), notice: 'Invoice tags successfully set'
+      redirect_to kaui_engine.invoice_path(invoice_id, account_id: account_id), notice: 'Invoice tags successfully set'
     end
   end
 end
diff --git a/app/helpers/kaui/date_helper.rb b/app/helpers/kaui/date_helper.rb
index 4fc155f1..03880496 100644
--- a/app/helpers/kaui/date_helper.rb
+++ b/app/helpers/kaui/date_helper.rb
@@ -17,7 +17,7 @@ def format_date(date, timezone)
 
       # If not, convert into account timezone and return the date part only
       parsed_date = DateTime.parse(date.to_s).in_time_zone(timezone)
-      parsed_date.to_fs(:date_only)
+      parsed_date.to_s(:date_only)
     end
 
     def truncate_millis(date_s)
diff --git a/app/helpers/kaui/plugin_helper.rb b/app/helpers/kaui/plugin_helper.rb
index 856e7ec8..f3f9919c 100644
--- a/app/helpers/kaui/plugin_helper.rb
+++ b/app/helpers/kaui/plugin_helper.rb
@@ -21,7 +21,7 @@ def installed_plugins
         plugin_key = plugin.plugin_key
         installed_plugins << {
           # Unique identifier chosen by the user and used for kpm operations
-          plugin_key:,
+          plugin_key: plugin_key,
           # Notes:
           #   * plugin.plugin_name comes from kpm and is arbitrary (see Utils.get_plugin_name_from_file_path in the kpm codebase for instance)
           #   * plugin_name here is the plugin name as seen by Kill Bill and is typically defined in the Activator.java (this value is the one that matters for plugin configuration)
diff --git a/app/helpers/kaui/uuid_helper.rb b/app/helpers/kaui/uuid_helper.rb
index 8355c200..c3ed3986 100644
--- a/app/helpers/kaui/uuid_helper.rb
+++ b/app/helpers/kaui/uuid_helper.rb
@@ -12,10 +12,10 @@ def truncate_uuid(uuid)
 
     def object_id_popover(object_id, placement = 'right', title = nil)
       content_tag(:span, truncate_uuid(object_id),
-                  id: "#{object_id}-popover", class: 'object-id-popover', title:,
+                  id: "#{object_id}-popover", class: 'object-id-popover', title: title,
                   data: {
                     id: object_id,
-                    placement:
+                    placement: placement
                   })
     end
   end
diff --git a/app/models/kaui/account_email.rb b/app/models/kaui/account_email.rb
index ec8b64f6..bd520f86 100644
--- a/app/models/kaui/account_email.rb
+++ b/app/models/kaui/account_email.rb
@@ -3,17 +3,17 @@
 module Kaui
   class AccountEmail < KillBillClient::Model::AccountEmailAttributes
     def self.find_all_sorted_by_account_id(account_id, audit = 'NONE', options = {})
-      emails = Kaui::Account.new(account_id:).emails(audit, options)
+      emails = Kaui::Account.new(account_id: account_id).emails(audit, options)
       emails.map { |email| Kaui::AccountEmail.new(email.to_hash) }.sort
     end
 
     def create(user = nil, reason = nil, comment = nil, options = {})
-      account = Kaui::Account.new(account_id:)
+      account = Kaui::Account.new(account_id: account_id)
       account.add_email(email, user, reason, comment, options)
     end
 
     def destroy(user = nil, reason = nil, comment = nil, options = {})
-      account = Kaui::Account.new(account_id:)
+      account = Kaui::Account.new(account_id: account_id)
       account.remove_email(email, user, reason, comment, options)
     end
 
diff --git a/app/models/kaui/admin.rb b/app/models/kaui/admin.rb
index 1eae8ca1..ebeb3fb7 100644
--- a/app/models/kaui/admin.rb
+++ b/app/models/kaui/admin.rb
@@ -27,9 +27,9 @@ def fix_transaction_state(payment_id, transaction_id, transaction_status, user =
                                 { transactionStatus: transaction_status }.to_json,
                                 {},
                                 {
-                                  user:,
-                                  reason:,
-                                  comment:
+                                  user: user,
+                                  reason: reason,
+                                  comment: comment
                                 }.merge(options)
       end
 
diff --git a/app/models/kaui/killbill_authenticatable.rb b/app/models/kaui/killbill_authenticatable.rb
index a429c936..babdfa43 100644
--- a/app/models/kaui/killbill_authenticatable.rb
+++ b/app/models/kaui/killbill_authenticatable.rb
@@ -31,8 +31,8 @@ module ClassMethods
         # Invoked by the KillbillAuthenticatable strategy to lookup the user
         # before attempting authentication
         def find_for_killbill_authentication(kb_username)
-          find_for_authentication(kb_username:) ||
-            new(kb_username:)
+          find_for_authentication(kb_username: kb_username) ||
+            new(kb_username: kb_username)
         rescue KillBillClient::API::Unauthorized => _e
           # Multi-Tenancy was enabled, but the tenant_id couldn't be retrieved because of bad credentials
           nil
diff --git a/config/initializers/killbill_authenticatable.rb b/config/initializers/killbill_authenticatable.rb
index 14a37944..c8ca097f 100644
--- a/config/initializers/killbill_authenticatable.rb
+++ b/config/initializers/killbill_authenticatable.rb
@@ -28,7 +28,7 @@ def authenticate!
         return false unless valid_password?
 
         user = params[:user] || {}
-        kb_authenticate!(user[:kb_username], { username: user[:kb_username], password: })
+        kb_authenticate!(user[:kb_username], { username: user[:kb_username], password: password })
       end
     end
 
@@ -77,7 +77,7 @@ def token
   unless user.authenticated_with_killbill?
     scope = opts[:scope]
     auth.logout(scope)
-    throw(:warden, scope:, reason: 'Kill Bill session expired')
+    throw(:warden, scope: scope, reason: 'Kill Bill session expired')
   end
 end
 
diff --git a/kaui.gemspec b/kaui.gemspec
index d6c47153..1a4b4ded 100644
--- a/kaui.gemspec
+++ b/kaui.gemspec
@@ -10,7 +10,7 @@ Gem::Specification.new do |s|
   s.summary = 'Killbill Admin UI mountable engine'
   s.description = 'Rails UI plugin for Killbill administration.'
 
-  s.required_ruby_version = '>= 2.7.0'
+  s.required_ruby_version = '>= 2.6.0'
 
   s.license = 'Apache License (2.0)'
 
@@ -38,12 +38,12 @@ Gem::Specification.new do |s|
   s.add_dependency 'jquery-ui-rails'
   s.add_dependency 'js-routes'
   s.add_dependency 'jwt'
-  s.add_dependency 'kenui'
+  s.add_dependency 'kenui', '~> 2.1.0'
   s.add_dependency 'killbill-client'
   s.add_dependency 'money-rails'
   s.add_dependency 'mustache-js-rails'
   s.add_dependency 'popper_js', '~> 2.11.5'
-  s.add_dependency 'rails', '~> 7.0'
+  s.add_dependency 'rails', '~> 6.1'
   s.add_dependency 'sass'
   s.add_dependency 'sassc-rails', '>= 2.1.0'
   s.add_dependency 'sass-rails'
diff --git a/lib/kaui.rb b/lib/kaui.rb
index c6735339..7d9d90df 100644
--- a/lib/kaui.rb
+++ b/lib/kaui.rb
@@ -202,12 +202,3 @@ def self.config
     }
   end
 end
-
-# ruby-1.8 compatibility
-module Kernel
-  def define_singleton_method(*args, &)
-    class << self
-      self
-    end.send(:define_method, *args, &)
-  end
-end
diff --git a/lib/kaui/version.rb b/lib/kaui/version.rb
index a4833671..ca40d165 100644
--- a/lib/kaui/version.rb
+++ b/lib/kaui/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Kaui
-  VERSION = '3.0.1'
+  VERSION = '2.2.1'
 end
diff --git a/test/dummy/config/application.rb b/test/dummy/config/application.rb
index f8b8fda2..37c4fd6f 100644
--- a/test/dummy/config/application.rb
+++ b/test/dummy/config/application.rb
@@ -22,7 +22,7 @@
 module Dummy
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.
-    config.load_defaults 7.0
+    config.load_defaults 6.1
 
     # Configuration for the application, engines, and railties goes here.
     #
diff --git a/test/functional/kaui/account_emails_controller_test.rb b/test/functional/kaui/account_emails_controller_test.rb
index 7d97e893..f7367691 100644
--- a/test/functional/kaui/account_emails_controller_test.rb
+++ b/test/functional/kaui/account_emails_controller_test.rb
@@ -21,7 +21,7 @@ class AccountEmailsControllerTest < Kaui::FunctionalTestHelper
     test 'should handle Kill Bill errors during creation' do
       account_id = SecureRandom.uuid.to_s
       post :create,
-           params: { account_id:,
+           params: { account_id: account_id,
                      account_email: {
                        email: 'toto@example.com'
                      } }
@@ -31,7 +31,7 @@ class AccountEmailsControllerTest < Kaui::FunctionalTestHelper
 
     test 'should handle Kill Bill errors during deletion' do
       account_id = 'invalid-id'
-      delete :destroy, params: { account_id:, id: 'toto@example.com' }
+      delete :destroy, params: { account_id: account_id, id: 'toto@example.com' }
       assert_redirected_to account_path(account_id)
     end
 
@@ -45,7 +45,7 @@ class AccountEmailsControllerTest < Kaui::FunctionalTestHelper
            params: {
              account_id: @account.account_id,
              account_email: {
-               email:
+               email: email
              }
            }
       assert_redirected_to account_path(@account.account_id)
diff --git a/test/functional/kaui/account_tags_controller_test.rb b/test/functional/kaui/account_tags_controller_test.rb
index 99e3a1ca..6a5410c3 100644
--- a/test/functional/kaui/account_tags_controller_test.rb
+++ b/test/functional/kaui/account_tags_controller_test.rb
@@ -6,7 +6,7 @@ module Kaui
   class AccountTagsControllerTest < Kaui::FunctionalTestHelper
     test 'should handle Kill Bill errors when getting edit screen' do
       account_id = '1234'
-      get :edit, params: { account_id: }
+      get :edit, params: { account_id: account_id }
       assert_redirected_to account_path(account_id)
     end
 
diff --git a/test/functional/kaui/accounts_controller_test.rb b/test/functional/kaui/accounts_controller_test.rb
index 55f80760..541a0988 100644
--- a/test/functional/kaui/accounts_controller_test.rb
+++ b/test/functional/kaui/accounts_controller_test.rb
@@ -43,7 +43,7 @@ class AccountsControllerTest < Kaui::FunctionalTestHelper
 
     test 'should handle Kill Bill errors when showing account details' do
       account_id = SecureRandom.uuid.to_s
-      get :show, params: { account_id: }
+      get :show, params: { account_id: account_id }
       assert_redirected_to home_path
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{account_id} type=ACCOUNT doesn't exist!", flash[:error]
     end
@@ -98,10 +98,10 @@ class AccountsControllerTest < Kaui::FunctionalTestHelper
       assert_equal 'Required parameter missing: account', flash[:error]
 
       external_key = SecureRandom.uuid.to_s
-      post :create, params: { account: { external_key: } }
+      post :create, params: { account: { external_key: external_key } }
       assert_redirected_to account_path(assigns(:account).account_id)
 
-      post :create, params: { account: { external_key: } }
+      post :create, params: { account: { external_key: external_key } }
       assert_template :new
       assert_equal "Error while creating account: Account already exists for key #{external_key}", flash[:error]
     end
@@ -156,7 +156,7 @@ class AccountsControllerTest < Kaui::FunctionalTestHelper
 
     test 'should handle Kill Bill errors when setting default payment method' do
       account_id = SecureRandom.uuid.to_s
-      put :set_default_payment_method, params: { account_id:, payment_method_id: @payment_method.payment_method_id }
+      put :set_default_payment_method, params: { account_id: account_id, payment_method_id: @payment_method.payment_method_id }
       assert_redirected_to home_path
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{account_id} type=ACCOUNT doesn't exist!", flash[:error]
     end
@@ -168,7 +168,7 @@ class AccountsControllerTest < Kaui::FunctionalTestHelper
 
     test 'should handle Kill Bill errors when paying all invoices' do
       account_id = SecureRandom.uuid.to_s
-      post :pay_all_invoices, params: { account_id: }
+      post :pay_all_invoices, params: { account_id: account_id }
       assert_redirected_to home_path
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{account_id} type=ACCOUNT doesn't exist!", flash[:error]
     end
@@ -226,10 +226,10 @@ class AccountsControllerTest < Kaui::FunctionalTestHelper
       assert_equal JSON[@response.body]['is_found'], false
 
       external_key = SecureRandom.uuid.to_s
-      post :create, params: { account: { external_key: } }
+      post :create, params: { account: { external_key: external_key } }
       assert_redirected_to account_path(redirected_account_id)
 
-      get :validate_external_key, params: { external_key: }
+      get :validate_external_key, params: { external_key: external_key }
       assert_response :success
       assert_equal JSON[@response.body]['is_found'], true
     end
diff --git a/test/functional/kaui/admin_allowed_users_controller_test.rb b/test/functional/kaui/admin_allowed_users_controller_test.rb
index 6aec6a4a..c0a46d97 100644
--- a/test/functional/kaui/admin_allowed_users_controller_test.rb
+++ b/test/functional/kaui/admin_allowed_users_controller_test.rb
@@ -88,7 +88,7 @@ class AdminAllowedUsersControllerTest < Kaui::FunctionalTestHelper
       assert response_path.include?(expected_response_path(id)), "#{response_path} is expected to contain #{expected_response_path(id)}"
 
       parameters = {
-        id:,
+        id: id,
         allowed_user: { description: 'An post-apocalyptic super hero' },
         roles: 'one,two'
       }
@@ -100,13 +100,13 @@ class AdminAllowedUsersControllerTest < Kaui::FunctionalTestHelper
       assert response_path.include?(expected_response_path(id)), "#{response_path} is expected to contain #{expected_response_path(id)}"
 
       # get the user to verify that the data was actually updated
-      get :edit, params: { id: }
+      get :edit, params: { id: id }
       description = extract_allowed_description
       assert_response :success
       assert_equal parameters[:allowed_user][:description], description
 
       # delete created user
-      delete :destroy, params: { id: }
+      delete :destroy, params: { id: id }
       assert_equal 'User was successfully deleted', flash[:notice]
       assert_response :redirect
       # validate redirect path
@@ -126,14 +126,14 @@ class AdminAllowedUsersControllerTest < Kaui::FunctionalTestHelper
       # validate redirect path
       assert response_path.include?(expected_response_path(id)), "#{response_path} is expected to contain #{expected_response_path(id)}"
 
-      delete :destroy, params: { id: }
+      delete :destroy, params: { id: id }
       assert_equal 'User was successfully deleted', flash[:notice]
       assert_response :redirect
       # validate redirect path
       assert response_path.include?(expected_response_path), "#{response_path} is expected to contain #{expected_response_path}"
 
       # should respond with an error if tried to delete again
-      delete :destroy, params: { id: }
+      delete :destroy, params: { id: id }
       assert_equal "Error: Couldn't find Kaui::AllowedUser with 'id'=#{id}", flash[:error]
       assert_response :redirect
       # validate redirect path
@@ -151,7 +151,7 @@ class AdminAllowedUsersControllerTest < Kaui::FunctionalTestHelper
 
       allowed_user[:id] = au.id
 
-      put :add_tenant, params: { allowed_user:, tenant_1: nil }
+      put :add_tenant, params: { allowed_user: allowed_user, tenant_1: nil }
       assert_equal 'Successfully set tenants for user', flash[:notice]
       assert_response :redirect
       # validate redirect path
diff --git a/test/functional/kaui/admin_tenants_controller_test.rb b/test/functional/kaui/admin_tenants_controller_test.rb
index 6aa59ac5..eeab8156 100644
--- a/test/functional/kaui/admin_tenants_controller_test.rb
+++ b/test/functional/kaui/admin_tenants_controller_test.rb
@@ -141,7 +141,7 @@ class AdminTenantsControllerTest < Kaui::FunctionalTestHelper
       assert_redirected_to admin_tenant_path(tenant.id)
       assert_equal I18n.translate('flashes.notices.catalog_uploaded_successfully'), flash[:notice]
 
-      get :new_plan_currency, params: { id: tenant.id, plan_id: }
+      get :new_plan_currency, params: { id: tenant.id, plan_id: plan_id }
       assert_response :success
       assert_equal extract_value_from_input_field('simple_plan_plan_id'), plan_id
 
@@ -238,7 +238,7 @@ class AdminTenantsControllerTest < Kaui::FunctionalTestHelper
       assert_redirected_to admin_tenant_path(tenant.id)
       assert_equal I18n.translate('flashes.notices.catalog_uploaded_successfully'), flash[:notice]
 
-      post :display_catalog_xml, params: { effective_date:, id: tenant.id }
+      post :display_catalog_xml, params: { effective_date: effective_date, id: tenant.id }
 
       doc = nil
       assert_nothing_raised { doc = Nokogiri::XML(@response.body, &:strict) }
@@ -261,7 +261,7 @@ class AdminTenantsControllerTest < Kaui::FunctionalTestHelper
       tenant = create_kaui_tenant
       post :upload_catalog, params: { id: tenant.id, catalog: fixture_file_upload("#{FIXTURES_PATH}/catalog-v1.xml") }
 
-      get :catalog_by_effective_date, params: { id: tenant.id, effective_date: }
+      get :catalog_by_effective_date, params: { id: tenant.id, effective_date: effective_date }
       assert_response :success
 
       result = nil
@@ -325,7 +325,7 @@ class AdminTenantsControllerTest < Kaui::FunctionalTestHelper
       assert_redirected_to admin_tenant_path(tenant.id)
       assert_equal I18n.translate('flashes.notices.catalog_uploaded_successfully'), flash[:notice]
 
-      get :download_catalog_xml, params: { effective_date:, id: tenant.id }
+      get :download_catalog_xml, params: { effective_date: effective_date, id: tenant.id }
       assert_response :success
       assert_equal 'application/xml', @response.header['Content-Type']
       assert_equal ActionDispatch::Http::ContentDisposition.format(disposition: 'attachment', filename: "catalog_#{effective_date}.xml"), @response.header['Content-Disposition']
diff --git a/test/functional/kaui/bundle_tags_controller_test.rb b/test/functional/kaui/bundle_tags_controller_test.rb
index 063bfe73..be7efc86 100644
--- a/test/functional/kaui/bundle_tags_controller_test.rb
+++ b/test/functional/kaui/bundle_tags_controller_test.rb
@@ -10,7 +10,7 @@ class BundleTagsControllerTest < Kaui::FunctionalTestHelper
       assert_equal 'Required parameter missing: bundle_id', flash[:error]
 
       bundle_id = SecureRandom.uuid.to_s
-      get :edit, params: { account_id: @account.account_id, bundle_id: }
+      get :edit, params: { account_id: @account.account_id, bundle_id: bundle_id }
       assert_redirected_to account_path(@account.account_id)
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{bundle_id} type=BUNDLE doesn't exist!", flash[:error]
     end
diff --git a/test/functional/kaui/bundles_controller_test.rb b/test/functional/kaui/bundles_controller_test.rb
index 98ede16d..74d04ba2 100644
--- a/test/functional/kaui/bundles_controller_test.rb
+++ b/test/functional/kaui/bundles_controller_test.rb
@@ -6,7 +6,7 @@ module Kaui
   class BundlesControllerTest < Kaui::FunctionalTestHelper
     test 'should be redirected if an invalid account id was specified in index screen' do
       account_id = SecureRandom.uuid.to_s
-      get :index, params: { account_id: }
+      get :index, params: { account_id: account_id }
       assert_redirected_to account_path(account_id)
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{account_id} type=ACCOUNT doesn't exist!", flash[:error]
     end
@@ -34,7 +34,7 @@ class BundlesControllerTest < Kaui::FunctionalTestHelper
       assert_equal 'Required parameter missing: new_account_key', flash[:error]
 
       new_account_key = SecureRandom.uuid.to_s
-      post :do_transfer, params: { id: @bundle.bundle_id, new_account_key: }
+      post :do_transfer, params: { id: @bundle.bundle_id, new_account_key: new_account_key }
       assert_redirected_to home_path
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{new_account_key} type=ACCOUNT doesn't exist!", flash[:error]
 
diff --git a/test/functional/kaui/chargebacks_controller_test.rb b/test/functional/kaui/chargebacks_controller_test.rb
index 4f4b23cc..b69f73bc 100644
--- a/test/functional/kaui/chargebacks_controller_test.rb
+++ b/test/functional/kaui/chargebacks_controller_test.rb
@@ -6,7 +6,7 @@ module Kaui
   class ChargebacksControllerTest < Kaui::FunctionalTestHelper
     test 'should handle Kill Bill errors in new screen' do
       payment_id = SecureRandom.uuid.to_s
-      get :new, params: { account_id: @account.account_id, payment_id: }
+      get :new, params: { account_id: @account.account_id, payment_id: payment_id }
       assert_redirected_to account_path(@account.account_id)
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{payment_id} type=PAYMENT doesn't exist!", flash[:error]
     end
@@ -22,7 +22,7 @@ class ChargebacksControllerTest < Kaui::FunctionalTestHelper
            params: {
              account_id: @account.account_id,
              chargeback: {
-               payment_id:,
+               payment_id: payment_id,
                amount: @payment.paid_amount_to_money.to_f,
                currency: @payment.currency
              }
diff --git a/test/functional/kaui/charges_controller_test.rb b/test/functional/kaui/charges_controller_test.rb
index d283398b..ce6e53f3 100644
--- a/test/functional/kaui/charges_controller_test.rb
+++ b/test/functional/kaui/charges_controller_test.rb
@@ -6,7 +6,7 @@ module Kaui
   class ChargesControllerTest < Kaui::FunctionalTestHelper
     test 'should handle Kill Bill errors in new screen' do
       invoice_id = SecureRandom.uuid.to_s
-      get :new, params: { account_id: @account.account_id, invoice_id: }
+      get :new, params: { account_id: @account.account_id, invoice_id: invoice_id }
       assert_redirected_to account_path(@account.account_id)
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{invoice_id} type=INVOICE doesn't exist!", flash[:error]
     end
@@ -27,7 +27,7 @@ class ChargesControllerTest < Kaui::FunctionalTestHelper
            params: {
              account_id: @account.account_id,
              invoice_item: {
-               invoice_id:,
+               invoice_id: invoice_id,
                amount: 5.34,
                currency: 'USD',
                description: SecureRandom.uuid
diff --git a/test/functional/kaui/credits_controller_test.rb b/test/functional/kaui/credits_controller_test.rb
index 8be0f25a..5dd5575f 100644
--- a/test/functional/kaui/credits_controller_test.rb
+++ b/test/functional/kaui/credits_controller_test.rb
@@ -6,7 +6,7 @@ module Kaui
   class CreditsControllerTest < Kaui::FunctionalTestHelper
     test 'should handle Kill Bill errors in new screen' do
       invoice_id = SecureRandom.uuid.to_s
-      get :new, params: { account_id: @account.account_id, invoice_id: }
+      get :new, params: { account_id: @account.account_id, invoice_id: invoice_id }
       assert_redirected_to account_path(@account.account_id)
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{invoice_id} type=INVOICE doesn't exist!", flash[:error]
     end
@@ -27,7 +27,7 @@ class CreditsControllerTest < Kaui::FunctionalTestHelper
            params: {
              account_id: @account.account_id,
              credit: {
-               invoice_id:,
+               invoice_id: invoice_id,
                amount: 5.34
              }
            }
diff --git a/test/functional/kaui/custom_fields_controller_test.rb b/test/functional/kaui/custom_fields_controller_test.rb
index 2e4f00aa..814949de 100644
--- a/test/functional/kaui/custom_fields_controller_test.rb
+++ b/test/functional/kaui/custom_fields_controller_test.rb
@@ -38,8 +38,8 @@ class CustomFieldsControllerTest < Kaui::FunctionalTestHelper
         post :create,
              params: {
                custom_field: {
-                 object_id:,
-                 object_type:,
+                 object_id: object_id,
+                 object_type: object_type,
                  name: SecureRandom.uuid.to_s,
                  value: SecureRandom.uuid.to_s
                }
diff --git a/test/functional/kaui/home_controller_test.rb b/test/functional/kaui/home_controller_test.rb
index 786278fc..e596d23f 100644
--- a/test/functional/kaui/home_controller_test.rb
+++ b/test/functional/kaui/home_controller_test.rb
@@ -393,8 +393,8 @@ def create_custom_field
 
     def create_account_tag_definition(name = 'account', description = 'i am an account')
       tag_definition = Kaui::TagDefinition.new({ is_control_tag: false,
-                                                 name:,
-                                                 description:,
+                                                 name: name,
+                                                 description: description,
                                                  applicable_object_types: ['ACCOUNT'] })
 
       tag_definition.create('kaui search test', nil, nil, build_options(@tenant, USERNAME, PASSWORD))
diff --git a/test/functional/kaui/invoice_items_controller_test.rb b/test/functional/kaui/invoice_items_controller_test.rb
index f7183f2f..683dc3da 100644
--- a/test/functional/kaui/invoice_items_controller_test.rb
+++ b/test/functional/kaui/invoice_items_controller_test.rb
@@ -10,7 +10,7 @@ class InvoiceItemsControllerTest < Kaui::FunctionalTestHelper
       assert_equal 'Required parameter missing: invoice_id', flash[:error]
 
       invoice_id = SecureRandom.uuid.to_s
-      get :edit, params: { account_id: @account.account_id, id: @invoice_item.invoice_item_id, invoice_id: }
+      get :edit, params: { account_id: @account.account_id, id: @invoice_item.invoice_item_id, invoice_id: invoice_id }
       assert_redirected_to account_path(@account.account_id)
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{invoice_id} type=INVOICE doesn't exist!", flash[:error]
 
@@ -32,7 +32,7 @@ class InvoiceItemsControllerTest < Kaui::FunctionalTestHelper
           params: { id: @invoice_item.invoice_item_id,
                     invoice_item: {
                       account_id: @account.account_id,
-                      invoice_id:,
+                      invoice_id: invoice_id,
                       invoice_item_id: @invoice_item.invoice_item_id,
                       amount: 5.34,
                       currency: :USD
@@ -68,7 +68,7 @@ class InvoiceItemsControllerTest < Kaui::FunctionalTestHelper
       delete :destroy,
              params: {
                id: @cba.invoice_item_id,
-               invoice_id:,
+               invoice_id: invoice_id,
                account_id: @account.account_id
              }
       assert_redirected_to account_path(@account.account_id)
diff --git a/test/functional/kaui/refunds_controller_test.rb b/test/functional/kaui/refunds_controller_test.rb
index b2203051..3af95b29 100644
--- a/test/functional/kaui/refunds_controller_test.rb
+++ b/test/functional/kaui/refunds_controller_test.rb
@@ -6,12 +6,12 @@ module Kaui
   class RefundsControllerTest < Kaui::FunctionalTestHelper
     test 'should handle Kill Bill errors in new screen' do
       invoice_id = SecureRandom.uuid.to_s
-      get :new, params: { account_id: @account.account_id, invoice_id:, payment_id: @payment.payment_id }
+      get :new, params: { account_id: @account.account_id, invoice_id: invoice_id, payment_id: @payment.payment_id }
       assert_redirected_to account_path(@account.account_id)
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{invoice_id} type=INVOICE doesn't exist!", flash[:error]
 
       payment_id = SecureRandom.uuid.to_s
-      get :new, params: { account_id: @account.account_id, invoice_id: @paid_invoice_item.invoice_id, payment_id: }
+      get :new, params: { account_id: @account.account_id, invoice_id: @paid_invoice_item.invoice_id, payment_id: payment_id }
       assert_redirected_to account_path(@account.account_id)
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{payment_id} type=PAYMENT doesn't exist!", flash[:error]
     end
diff --git a/test/functional/kaui/role_definitions_controller_test.rb b/test/functional/kaui/role_definitions_controller_test.rb
index 23db5dfa..c39ea996 100644
--- a/test/functional/kaui/role_definitions_controller_test.rb
+++ b/test/functional/kaui/role_definitions_controller_test.rb
@@ -29,7 +29,7 @@ class RoleDefinitionsControllerTest < Kaui::FunctionalTestHelper
       role_definition['role'] = "test#{SecureRandom.base64(9).gsub(%r{[/+=]}, '')}"
       role_definition['permissions'] = 'account:delete_emails,account:add_emails'
 
-      post :create, params: { role_definition: }
+      post :create, params: { role_definition: role_definition }
 
       assert_equal 'Role was successfully created', flash[:notice]
       assert_response :redirect
@@ -41,7 +41,7 @@ class RoleDefinitionsControllerTest < Kaui::FunctionalTestHelper
       role_definition['role'] = "test#{SecureRandom.base64(9).gsub(%r{[/+=]}, '')}"
       role_definition['permissions'] = 'account:delete_emails,account:add_emails'
 
-      post :create, params: { role_definition:, reason: SecureRandom.base64(4000), comment: SecureRandom.base64(4000) }
+      post :create, params: { role_definition: role_definition, reason: SecureRandom.base64(4000), comment: SecureRandom.base64(4000) }
       assert_match 'Error while creating role', flash[:error]
       assert_response :success
     end
diff --git a/test/functional/kaui/subscriptions_controller_test.rb b/test/functional/kaui/subscriptions_controller_test.rb
index 170d2caa..f56b787b 100644
--- a/test/functional/kaui/subscriptions_controller_test.rb
+++ b/test/functional/kaui/subscriptions_controller_test.rb
@@ -7,7 +7,7 @@ class SubscriptionsControllerTest < Kaui::FunctionalTestHelper
     OVERRIDE_CATALOG = 'test/fixtures/catalog-sample-for-cancel-subscription.xml'
     test 'should handle Kill Bill errors in new screen' do
       bundle_id = SecureRandom.uuid.to_s
-      get :new, params: { bundle_id:, account_id: @account.account_id, product_category: 'ADD_ON' }
+      get :new, params: { bundle_id: bundle_id, account_id: @account.account_id, product_category: 'ADD_ON' }
       assert_redirected_to account_path(@account.account_id)
       assert_equal "Error while communicating with the Kill Bill server: Object id=#{bundle_id} type=BUNDLE doesn't exist!", flash[:error]
     end
diff --git a/test/functional/kaui/transactions_controller_test.rb b/test/functional/kaui/transactions_controller_test.rb
index a2ccb700..58174b8c 100644
--- a/test/functional/kaui/transactions_controller_test.rb
+++ b/test/functional/kaui/transactions_controller_test.rb
@@ -49,7 +49,7 @@ class TransactionsControllerTest < Kaui::FunctionalTestHelper
                  payment_external_key: SecureRandom.uuid,
                  amount: 12,
                  currency: 'USD',
-                 transaction_type:
+                 transaction_type: transaction_type
                }
              }
 
@@ -64,10 +64,10 @@ class TransactionsControllerTest < Kaui::FunctionalTestHelper
              params: {
                account_id: @account.account_id,
                transaction: {
-                 payment_id:,
+                 payment_id: payment_id,
                  amount: 12,
                  currency: 'USD',
-                 transaction_type:
+                 transaction_type: transaction_type
                }
              }
         assert_redirected_to account_payment_path(@account.account_id, payment_id)
diff --git a/test/killbill_test_helper.rb b/test/killbill_test_helper.rb
index 66272ad9..60898e7c 100644
--- a/test/killbill_test_helper.rb
+++ b/test/killbill_test_helper.rb
@@ -163,7 +163,7 @@ def create_cba(invoice_id = nil, account = nil, tenant = nil, _auto_commit = fal
       tenant  = create_tenant(user, reason, comment) if tenant.nil?
       account = create_account(tenant, username, password, user, reason, comment) if account.nil?
 
-      credit = KillBillClient::Model::Credit.new(invoice_id:, account_id: account.account_id, amount: 23.22)
+      credit = KillBillClient::Model::Credit.new(invoice_id: invoice_id, account_id: account.account_id, amount: 23.22)
       credit = credit.create(true, user, reason, comment, build_options(tenant, username, password)).first
 
       invoice = KillBillClient::Model::Invoice.find_by_id(credit.invoice_id, 'NONE', build_options(tenant, username, password))
@@ -212,8 +212,8 @@ def build_options(tenant = nil, username = USERNAME, password = PASSWORD)
       {
         api_key: tenant&.api_key,
         api_secret: tenant&.api_secret,
-        username:,
-        password:
+        username: username,
+        password: password
       }
     end