diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index a06a6b5..dd10f7a 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -20,6 +20,8 @@ updates:
         patterns:
           - '*rubocop*'
   - package-ecosystem: 'bundler'
+    # For feature dependedncy updates,
+    # Keep this definition even if the /gemfiles/oldest/Gemfile is completely same as /Gemfile
     directory: '/gemfiles/oldest'
     schedule:
       interval: 'weekly'
diff --git a/README.md b/README.md
index 60c39b7..96b9aae 100644
--- a/README.md
+++ b/README.md
@@ -46,28 +46,6 @@ $ irb
 
 Then you can use `pa` as an IRB command.
 
-```ruby
-irb(main):001:0> pa %q{ "0".class == "3".to_i.times.map {|i| i + 1 }.class }
-result: false
-
- "0".class == "3".to_i.times.map {|i| i + 1 }.class
-     |     |      |    |     |                |
-     |     |      |    |     |                Array
-     |     |      |    |     [1, 2, 3]
-     |     |      |    #<Enumerator: ...>
-     |     |      3
-     |     false
-     String
-=> nil
-```
-
-The `pa` just takes strings of the code.
-
-If you want to directly pass `expression`, [.irbrc](examples/.irbrc) is the hack for single line code.\
-if you don't have the file yet, putting the file as one of your `$IRBRC`, `$XDG_CONFIG_HOME/irb/irbrc` or `$HOME/.irbrc`
-
-Then you can use the `pa` as below...
-
 ```ruby
 irb(main):001:0> pa "0".class == "3".to_i.times.map {|i| i + 1 }.class
 result: false
@@ -83,8 +61,11 @@ result: false
 => nil
 ```
 
+No hack is needed in your irbrc, thank you irb developers!
+
 ## References
 
 - [power-assert-js/power-assert](https://github.com/power-assert-js/power-assert)
 - [Power Assert in Ruby](https://speakerdeck.com/k_tsj/power-assert-in-ruby)
 - [ja - IRB is new than Pry](https://k0kubun.hatenablog.com/entry/2021/04/02/211455)
+- [Support command registration](https://github.com/ruby/irb/pull/886)
diff --git a/examples/.irbrc b/examples/.irbrc
deleted file mode 100644
index 8158c7d..0000000
--- a/examples/.irbrc
+++ /dev/null
@@ -1,19 +0,0 @@
-# frozen_string_literal: true
-
-require 'irb/power_assert'
-
-# This logic taken from following reference, @k0kubun thank you!
-#  * https://github.com/k0kubun/dotfiles/blob/8762ee623adae0fba20ed0a5ef7c8ff5825dc20a/config/.irbrc#L241-L262
-#  * https://k0kubun.hatenablog.com/entry/2021/04/02/211455
-IRB::Context.prepend(Module.new{
-  kwargs = Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.7.0') ? ', **' : ''
-  line = __LINE__; eval %q{
-    def evaluate(line, *__ARGS__)
-      case line
-      when /\Apa /
-        line.replace("pa #{line.sub(/\Apa +/, '').strip.dump}\n")
-      end
-      super
-    end
-  }.sub(/__ARGS__/, kwargs), nil, __FILE__, line
-})
diff --git a/gemfiles/oldest/Gemfile b/gemfiles/oldest/Gemfile
index a78d1cb..4abd2e9 100644
--- a/gemfiles/oldest/Gemfile
+++ b/gemfiles/oldest/Gemfile
@@ -15,6 +15,6 @@ group :test do
   gem 'test-unit', '~> 3.6.2'
   gem 'warning', '~> 1.3.0'
 
-  gem 'irb', '1.12.0'
+  gem 'irb', '1.13.0'
   gem 'power_assert', '2.0.3'
 end
diff --git a/irb-power_assert.gemspec b/irb-power_assert.gemspec
index 12db26b..ddc37f2 100644
--- a/irb-power_assert.gemspec
+++ b/irb-power_assert.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |gem|
     'rubygems_mfa_required' => 'true',
   }
 
-  gem.add_runtime_dependency 'irb', '>= 1.12.0', '< 2.0'
+  gem.add_runtime_dependency 'irb', '>= 1.13.0', '< 2.0'
   gem.add_runtime_dependency 'power_assert', '>= 2.0.3', '< 3.0'
 
   gem.required_ruby_version = '>= 3.2'
diff --git a/lib/irb/cmd/pa.rb b/lib/irb/cmd/pa.rb
index a383914..6615484 100644
--- a/lib/irb/cmd/pa.rb
+++ b/lib/irb/cmd/pa.rb
@@ -19,13 +19,5 @@ def execute(expression)
     end
   end
 
-  if ::IRB::Command.respond_to?(:register)
-    Command.register(:pa, PaCommand)
-  else
-    Command::Pa = PaCommand
-
-    module ExtendCommandBundle
-      def_extend_command(:irb_pa, :Pa, __FILE__, [:pa, NO_OVERRIDE])
-    end
-  end
+  Command.register(:pa, PaCommand)
 end
diff --git a/test/test_irb_power_assert.rb b/test/test_irb_power_assert.rb
index baa21c9..2a5a0d6 100644
--- a/test/test_irb_power_assert.rb
+++ b/test/test_irb_power_assert.rb
@@ -35,23 +35,10 @@ def test_typical_example
     EOD
 
     out, err = capture_output do
-      if ::IRB::Command.respond_to?(:register)
-        # Since ruby 3.4 (or newer irb gem), no need irbrc hack to realize `pa exp` instead of `pa 'exp'`
-        execute_lines(%q{pa "0".class == "3".to_i.times.map {|i| i + 1 }.class})
-      else
-        IRB.setup(__FILE__, argv: [])
-        IRB.conf[:USE_MULTILINE] = true
-        IRB.conf[:USE_SINGLELINE] = false
-        IRB.conf[:VERBOSE] = false
-        workspace = IRB::WorkSpace.new(self)
-        irb = IRB::Irb.new(workspace)
-        IRB.conf[:MAIN_CONTEXT] = irb.context
-
-        irb.context.main.irb_pa(%q{"0".class == "3".to_i.times.map {|i| i + 1 }.class})
-      end
+      execute_lines(%q{pa "0".class == "3".to_i.times.map {|i| i + 1 }.class})
     end
 
     assert_equal('', err)
-    assert_equal((::IRB::Command.respond_to?(:register) ? expected + "=> nil\n" : expected), out)
+    assert_equal(expected + "=> nil\n", out)
   end
 end