diff --git a/core/boot/option.rb b/core/boot/option.rb
index b97d28b..a698fa6 100644
--- a/core/boot/option.rb
+++ b/core/boot/option.rb
@@ -18,6 +18,10 @@ module Mopt
     scope.__send__(:define_method, key){ @opts[key.to_sym] }
     @opts[key.to_sym] end
 
+  def respond_to_missing?(key, include_private = false)
+    @opts.has_key? key.to_sym
+  end
+
   def parse(argv=ARGV, exec_command: false)
     unless argv.is_a? OptionParser::Arguable
       argv.extend(OptionParser::Arguable) end
diff --git a/core/lib/lazy.rb b/core/lib/lazy.rb
index 457f240..0676aca 100644
--- a/core/lib/lazy.rb
+++ b/core/lib/lazy.rb
@@ -19,6 +19,10 @@ class IrregularEval
   def method_missing(method, *args, &block)
     irregular_eval_object.__send__(method, *args, &block) end end
 
+  def respond_to_missing?(method, include_private = false)
+    irregular_eval_object.respond_to?(method, include_private)
+  end
+
 class Lazy < IrregularEval
 
   def initialize
diff --git a/core/lib/retriever/uri.rb b/core/lib/retriever/uri.rb
index 3884544..9d9daed 100644
--- a/core/lib/retriever/uri.rb
+++ b/core/lib/retriever/uri.rb
@@ -104,6 +104,10 @@ class Retriever::URI
     to_uri.__send__(method, *rest, &block)
   end
 
+  def respond_to_missing?(method, include_private = false)
+    to_uri.respond_to?(method, include_private)
+  end
+
   private
 
   def generate_uri
diff --git a/core/lib/test_unit_extensions.rb b/core/lib/test_unit_extensions.rb
index fe635e3..c7d7fa3 100644
--- a/core/lib/test_unit_extensions.rb
+++ b/core/lib/test_unit_extensions.rb
@@ -34,4 +34,7 @@ module Mopt
     scope.__send__(:define_method, key){ @opts[key.to_sym] }
     @opts[key.to_sym] end
 
+  def respond_to_missing?(key, include_private = false)
+    @opts.has_key? key.to_sym
+  end
 end
diff --git a/core/mui/cairo_timeline.rb b/core/mui/cairo_timeline.rb
index cdaa16c..03dda7f 100644
--- a/core/mui/cairo_timeline.rb
+++ b/core/mui/cairo_timeline.rb
@@ -127,6 +127,10 @@ class Gtk::TimeLine
   def method_missing(method_name, *args, &proc)
     @tl.__send__(method_name, *args, &proc) end
 
+  def respond_to_missing?(method_name, include_private = false)
+    @tl.respond_to?(method_name, include_private)
+  end
+
   protected
 
   # _message_ をTLに追加する
diff --git a/core/mui/gtk_form_dsl.rb b/core/mui/gtk_form_dsl.rb
index a1cc475..5afc3b7 100644
--- a/core/mui/gtk_form_dsl.rb
+++ b/core/mui/gtk_form_dsl.rb
@@ -351,6 +351,10 @@ module Gtk::FormDSL
     @plugin.__send__(*args, &block)
   end
 
+  def respond_to_missing?(symbol, include_private = false)
+    @plugin.respond_to?(symbol, include_private)
+  end
+
   private
 
   def about_converter
diff --git a/core/mui/gtk_form_dsl_select.rb b/core/mui/gtk_form_dsl_select.rb
index 7785f74..874d325 100644
--- a/core/mui/gtk_form_dsl_select.rb
+++ b/core/mui/gtk_form_dsl_select.rb
@@ -51,6 +51,10 @@ class Gtk::FormDSL::Select
     @parent_dslobj.method_missing(*args, &block)
   end
 
+  def respond_to_missing?(symbol, include_private = false)
+    @parent_dslobj.respond_to?(symbol, include_private)
+  end
+
   private
 
   def build_box(config_key)
diff --git a/core/plugin/achievement/achievement.rb b/core/plugin/achievement/achievement.rb
index 4f90f1d..c5c92b3 100644
--- a/core/plugin/achievement/achievement.rb
+++ b/core/plugin/achievement/achievement.rb
@@ -65,6 +65,10 @@ class Plugin::Achievement::Achievement
     result
   end
 
+  def respond_to_missing?(method, include_private = false)
+    plugin.respond_to?(method, include_private)
+  end
+
   private
 
   def _force_take!
diff --git a/core/plugin/activity/activity.rb b/core/plugin/activity/activity.rb
index 4e90aa7..0f387e4 100644
--- a/core/plugin/activity/activity.rb
+++ b/core/plugin/activity/activity.rb
@@ -55,6 +55,10 @@ Plugin.create(:activity) do
     def method_missing(*args, &block)
       @plugin.__send__(*args, &block)
     end
+
+    def respond_to_missing?(symbol, include_private = false)
+      @plugin.respond_to?(symbol, include_private)
+    end
   end
 
   BOOT_TIME = Time.new.freeze
diff --git a/core/plugin/change_account/world_generator/controller.rb b/core/plugin/change_account/world_generator/controller.rb
index a72c6ff..98d3425 100644
--- a/core/plugin/change_account/world_generator/controller.rb
+++ b/core/plugin/change_account/world_generator/controller.rb
@@ -36,4 +36,8 @@ class Plugin::ChangeAccount::WorldGenerator::Controller
     @plugin.__send__(*args, &block)
   end
 
+  def respond_to_missing?(symbol, include_private = false)
+    @plugin.respond_to?(symbol, include_private)
+  end
+
 end
diff --git a/core/plugin/extract/extract.rb b/core/plugin/extract/extract.rb
index 788bb51..ddfe826 100644
--- a/core/plugin/extract/extract.rb
+++ b/core/plugin/extract/extract.rb
@@ -52,6 +52,10 @@ module Plugin::Extract
       else
         super end end
 
+    def respond_to_missing?(method_name, include_private = false)
+      @operators.any?{ |_| _.slug == method_name }
+    end
+
     def call(*args)
       @condition.(*args, message: @message) end
   end
diff --git a/core/plugin/gui/widget.rb b/core/plugin/gui/widget.rb
index dfc32c1..468ab8b 100644
--- a/core/plugin/gui/widget.rb
+++ b/core/plugin/gui/widget.rb
@@ -97,4 +97,8 @@ module Plugin::GUI::Widget
     else
       super end end
 
+  def respond_to_missing?(symbol, include_private = false)
+    defined?(@delegate) and @delegate and @delegate.respond_to?(symbol, include_private)
+  end
+
 end
diff --git a/core/plugin/settings/phantom.rb b/core/plugin/settings/phantom.rb
index a67a8cb..10f6639 100644
--- a/core/plugin/settings/phantom.rb
+++ b/core/plugin/settings/phantom.rb
@@ -35,10 +35,23 @@ module Plugin::Settings
       end
     end
 
+    def respond_to_missing?(name, include_private = false)
+      case name.to_sym
+      when *Gtk::FormDSL.instance_methods
+        MOCK.respond_to?(name, include_private)
+      else
+        Plugin.instance(@plugin_slug).respond_to?(name, include_private)
+      end
+    end
+
     class Mock
       def method_missing(name, *rest, **kwrest, &block)
         MOCK
       end
+
+      def respond_to_missing?(name, include_private = false)
+        MOCK.respond_to?(name, include_private)
+      end
     end
 
     MOCK = Mock.new
diff --git a/core/plugin/twitter/model/world.rb b/core/plugin/twitter/model/world.rb
index 368111b..7d6da3b 100644
--- a/core/plugin/twitter/model/world.rb
+++ b/core/plugin/twitter/model/world.rb
@@ -178,6 +178,10 @@ module Plugin::Twitter
       result
     end
 
+    def respond_to_missing?(method_name, include_private = false)
+      twitter.respond_to?(method_name, include_private)
+    end
+
     # :nodoc:
     # 内部で利用するために用意されています。
     # ツイートを投稿したい場合は、