diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 3b40b29c..f0e84681 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -34,9 +34,7 @@ jobs:
             ruby: '3.1'
           - gemfile: gemfiles/Gemfile-rails-6-0
             env: DEVISE_ORM=mongoid
-    # TODO: lock `ubunty-20.04` due to older Ruby version compatibility, change to `ubuntu-latest` again when dropping older Ruby support.
-    # https://github.com/ruby/setup-ruby/issues/496#issuecomment-1520662740
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     env: # $BUNDLE_GEMFILE must be set at the job level, so it is set for all steps
       BUNDLE_GEMFILE: ${{ matrix.gemfile }}
     steps:
@@ -45,8 +43,6 @@ jobs:
         with:
           ruby-version: ${{ matrix.ruby }}
           bundler-cache: true # runs bundle install and caches installed gems automatically
-          bundler: ${{ env.BUNDLER_VERSION || 'default' }}
-          rubygems: ${{ env.RUBYGEMS_VERSION || 'latest' }}
       - uses: supercharge/mongodb-github-action@1.9.0
         if: ${{ matrix.env == 'DEVISE_ORM=mongoid' }}
       - run: bundle exec rake
diff --git a/README.md b/README.md
index caecead2..e76d8b3f 100644
--- a/README.md
+++ b/README.md
@@ -644,7 +644,7 @@ Unlike controller tests, integration tests do not need to supply the
 `devise.mapping` `env` value, as the mapping can be inferred by the routes that
 are executed in your tests.
 
-You can read more about testing your Rails 3 - Rails 4 controllers with RSpec in the wiki:
+You can read more about testing your Rails controllers with RSpec in the wiki:
 
 * https://github.com/heartcombo/devise/wiki/How-To:-Test-controllers-with-Rails-(and-RSpec)
 
diff --git a/bin/test b/bin/test
index 3670b19d..28141f2c 100755
--- a/bin/test
+++ b/bin/test
@@ -1,17 +1,12 @@
 #!/usr/bin/env ruby
 $: << File.expand_path(File.expand_path('../../test', __FILE__))
 
-# Remove this begin/rescue once Rails 4 support is removed.
-begin
-  require 'bundler/setup'
-  require 'rails/test_unit/runner'
-  require 'rails/test_unit/reporter'
-  require 'rails/test_unit/line_filtering'
+require 'bundler/setup'
+require 'rails/test_unit/runner'
+require 'rails/test_unit/reporter'
+require 'rails/test_unit/line_filtering'
 
-  Rails::TestUnitReporter.executable = 'bin/test'
+Rails::TestUnitReporter.executable = 'bin/test'
 
-  Rails::TestUnit::Runner.parse_options(ARGV)
-  Rails::TestUnit::Runner.run(ARGV)
-rescue LoadError
-  exec 'rake'
-end
+Rails::TestUnit::Runner.parse_options(ARGV)
+Rails::TestUnit::Runner.run(ARGV)
diff --git a/test/rails_app/app/controllers/streaming_controller.rb b/test/rails_app/app/controllers/streaming_controller.rb
index 5fd711c2..1045fea1 100644
--- a/test/rails_app/app/controllers/streaming_controller.rb
+++ b/test/rails_app/app/controllers/streaming_controller.rb
@@ -8,16 +8,4 @@ class StreamingController < ApplicationController
   def index
     render body: 'Index'
   end
-
-  # Work around https://github.com/heartcombo/devise/issues/2332, which affects
-  # tests in Rails 4.x (and affects production in Rails >= 5)
-  def process(name)
-    super(name)
-  rescue ArgumentError => e
-    if e.message == 'uncaught throw :warden'
-      throw :warden
-    else
-      raise e
-    end
-  end
 end
diff --git a/test/test_helper.rb b/test/test_helper.rb
index c0bb43f7..ad5a6db6 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -23,22 +23,6 @@ end
 if ActiveSupport.respond_to?(:test_order)
   ActiveSupport.test_order = :random
 end
-class ActiveSupport::TestCase
-  if ActiveSupport.version < Gem::Version.new("5.0")
-    def assert_deprecated(match, deprecator)
-      super(match) do
-        # TODO: remove extra begin..end when dropping support for Ruby <= 2.4
-        begin
-          behavior = deprecator.behavior
-          deprecator.behavior = ActiveSupport::Deprecation.behavior
-          yield
-        ensure
-          deprecator.behavior = behavior
-        end
-      end
-    end
-  end
-end
 
 OmniAuth.config.logger = Logger.new('/dev/null')