diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a877c1e..2795c4c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,9 +11,9 @@ jobs:
       fail-fast: false
       matrix:
         ruby:
-          - 2.6
-          - 2.7
-          # TODO: Add 3.0 after upgrading Rails
+          - '2.6'
+          - '2.7'
+          - '3.0'
     name: Run test with Ruby ${{ matrix.ruby }}
     services:
       mysql:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 28c85a1..8d8652f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## v2.x.x (xxxx-xx-xx)
+### Changes
+- Update Rails to 6.1
+- Support Ruby 3.0
+
 ## v2.8.0 (2021-12-23)
 ### New features
 - Pass `BARBEQUE_SENT_TIMESTAMP` variable to invoked jobs
diff --git a/app/services/barbeque/sns_subscription_service.rb b/app/services/barbeque/sns_subscription_service.rb
index 9f06dd0..577fa99 100644
--- a/app/services/barbeque/sns_subscription_service.rb
+++ b/app/services/barbeque/sns_subscription_service.rb
@@ -20,10 +20,10 @@ def subscribe(sns_subscription)
         update_sqs_policy!(sns_subscription)
         true
       rescue Aws::SNS::Errors::AuthorizationError
-        sns_subscription.errors[:topic_arn] << 'is not authorized'
+        sns_subscription.errors.add(:topic_arn, 'is not authorized')
         false
       rescue Aws::SNS::Errors::NotFound
-        sns_subscription.errors[:topic_arn] << 'is not found'
+        sns_subscription.errors.add(:topic_arn, 'is not found')
         false
       end
     else
diff --git a/barbeque.gemspec b/barbeque.gemspec
index 40f8d93..d721ffc 100644
--- a/barbeque.gemspec
+++ b/barbeque.gemspec
@@ -26,7 +26,7 @@ Gem::Specification.new do |s|
   s.add_dependency "hamlit"
   s.add_dependency "jquery-rails"
   s.add_dependency "kaminari", ">= 1.2.1"
-  s.add_dependency "rails", "~> 5.2.0"
+  s.add_dependency "rails", "~> 6.1.4"
   s.add_dependency "rinku"
   s.add_dependency "sass-rails"
   s.add_dependency "serverengine"
diff --git a/lib/barbeque/executor.rb b/lib/barbeque/executor.rb
index 5af3d1a..4b0a11b 100644
--- a/lib/barbeque/executor.rb
+++ b/lib/barbeque/executor.rb
@@ -23,7 +23,7 @@ module Barbeque
   module Executor
     def self.create
       klass = const_get(Barbeque.config.executor, false)
-      klass.new(Barbeque.config.executor_options)
+      klass.new(**Barbeque.config.executor_options)
     end
   end
 end
diff --git a/lib/barbeque/executor/docker.rb b/lib/barbeque/executor/docker.rb
index 561ea4e..b9b00dc 100644
--- a/lib/barbeque/executor/docker.rb
+++ b/lib/barbeque/executor/docker.rb
@@ -9,7 +9,7 @@ class Docker
       class DockerCommandError < StandardError
       end
 
-      def initialize(_options)
+      def initialize(**)
       end
 
       # @param [Barbeque::JobExecution] job_execution
diff --git a/lib/barbeque/executor/hako.rb b/lib/barbeque/executor/hako.rb
index fe576f3..d535f85 100644
--- a/lib/barbeque/executor/hako.rb
+++ b/lib/barbeque/executor/hako.rb
@@ -18,7 +18,7 @@ class HakoCommandError < StandardError
       # @param [String] yaml_dir (deprecated: renamed to definition_dir)
       def initialize(hako_dir:, hako_env: {}, yaml_dir: nil, definition_dir: nil, oneshot_notification_prefix:)
         @hako_dir = hako_dir
-        @hako_env = hako_env
+        @hako_env = hako_env.stringify_keys
         @definition_dir =
           if definition_dir
             definition_dir
diff --git a/spec/barbeque/execution_poller_spec.rb b/spec/barbeque/execution_poller_spec.rb
index f24fe17..9a67e30 100644
--- a/spec/barbeque/execution_poller_spec.rb
+++ b/spec/barbeque/execution_poller_spec.rb
@@ -7,7 +7,7 @@
   let(:executor) { double('Barbeque::Executor::Docker') }
 
   before do
-    allow(Barbeque::Executor::Docker).to receive(:new).with({}).and_return(executor)
+    allow(Barbeque::Executor::Docker).to receive(:new).and_return(executor)
   end
 
   describe '#run' do
diff --git a/spec/barbeque/executor/docker_spec.rb b/spec/barbeque/executor/docker_spec.rb
index cd138e5..f64d68e 100644
--- a/spec/barbeque/executor/docker_spec.rb
+++ b/spec/barbeque/executor/docker_spec.rb
@@ -2,7 +2,7 @@
 require 'barbeque/executor/docker'
 
 RSpec.describe Barbeque::Executor::Docker do
-  let(:executor) { described_class.new({}) }
+  let(:executor) { described_class.new }
   let(:command) { ['rake', 'test'] }
   let(:job_definition) { FactoryBot.create(:job_definition, command: ['rake', 'test']) }
   let(:job_execution) { FactoryBot.create(:job_execution, job_definition: job_definition, status: :pending) }
diff --git a/spec/barbeque/executor_spec.rb b/spec/barbeque/executor_spec.rb
index d7189f3..3c0271b 100644
--- a/spec/barbeque/executor_spec.rb
+++ b/spec/barbeque/executor_spec.rb
@@ -12,7 +12,12 @@
       let(:barbeque_yml) { 'barbeque' }
 
       it 'initializes a configured executor' do
-        expect(Barbeque::Executor::Docker).to receive(:new).with({})
+        if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('2.7.0')
+          # Ruby < 2.7 isn't ready for keyword arguments
+          expect(Barbeque::Executor::Docker).to receive(:new).with({})
+        else
+          expect(Barbeque::Executor::Docker).to receive(:new).with(no_args)
+        end
         Barbeque::Executor.create
       end
     end
@@ -23,11 +28,12 @@
       it 'initializes a configured executor with configured options' do
         expect(Barbeque::Executor::Hako).to receive(:new).with(
           hako_dir: '/home/k0kubun/hako_repo',
-          hako_env: { 'ACCESS_TOKEN' => 'token' },
+          hako_env: { ACCESS_TOKEN: 'token' },
           yaml_dir: '/yamls',
           oneshot_notification_prefix: 's3://barbeque/task_statuses?region=ap-northeast-1',
-        )
-        Barbeque::Executor.create
+        ).and_call_original
+        hako = Barbeque::Executor.create
+        expect(hako.instance_variable_get(:@hako_env)).to eq({ 'ACCESS_TOKEN' => 'token' })
       end
     end
   end
diff --git a/spec/barbeque/message_handler/job_execution_spec.rb b/spec/barbeque/message_handler/job_execution_spec.rb
index 4b4ed7e..3965e86 100644
--- a/spec/barbeque/message_handler/job_execution_spec.rb
+++ b/spec/barbeque/message_handler/job_execution_spec.rb
@@ -22,7 +22,7 @@
     let(:executor) { double('Barbeque::Executor::Docker') }
 
     before do
-      allow(Barbeque::Executor::Docker).to receive(:new).with({}).and_return(executor)
+      allow(Barbeque::Executor::Docker).to receive(:new).and_return(executor)
       allow(Barbeque::ExecutionLog).to receive(:save_message)
       allow(Barbeque::ExecutionLog).to receive(:save_stdout_and_stderr)
     end
diff --git a/spec/barbeque/message_handler/job_retry_spec.rb b/spec/barbeque/message_handler/job_retry_spec.rb
index 765628a..7bd91c5 100644
--- a/spec/barbeque/message_handler/job_retry_spec.rb
+++ b/spec/barbeque/message_handler/job_retry_spec.rb
@@ -22,7 +22,7 @@
     before do
       allow(Barbeque::ExecutionLog).to receive(:save_stdout_and_stderr)
       allow(Barbeque::ExecutionLog).to receive(:load).with(execution: job_execution).and_return({ 'message' => message_body })
-      allow(Barbeque::Executor::Docker).to receive(:new).with({}).and_return(executor)
+      allow(Barbeque::Executor::Docker).to receive(:new).and_return(executor)
     end
 
     around do |example|
diff --git a/spec/barbeque/retry_poller_spec.rb b/spec/barbeque/retry_poller_spec.rb
index 3b5f2dc..d700573 100644
--- a/spec/barbeque/retry_poller_spec.rb
+++ b/spec/barbeque/retry_poller_spec.rb
@@ -7,7 +7,7 @@
   let(:executor) { double('Barbeque::Executor::Docker') }
 
   before do
-    allow(Barbeque::Executor::Docker).to receive(:new).with({}).and_return(executor)
+    allow(Barbeque::Executor::Docker).to receive(:new).and_return(executor)
   end
 
   describe '#run' do