diff --git a/ChangeLog b/ChangeLog
index a284ca1849..d802014846 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Feb  5 16:25:25 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* vm_method.c (rb_obj_respond_to): drop optional include_all flag if
+	  respond_to? method is defined in old style.  [Bug #7722]
+
 Tue Feb 05 15:04:34 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* proc.c (rb_binding_new_with_cfp): permit to create binding object
diff --git a/test/ruby/test_marshal.rb b/test/ruby/test_marshal.rb
index 4dcdb605ab..722871424d 100644
--- a/test/ruby/test_marshal.rb
+++ b/test/ruby/test_marshal.rb
@@ -550,4 +550,16 @@ class TestMarshal < Test::Unit::TestCase
     assert_raise(TypeError) {Marshal.load("\x04\x08IM\x1cTestMarshal::TestModule\x06:\x0e@ivar_bug\"\x08bug")}
     assert_not_operator(TestModule, :instance_variable_defined?, :@bug)
   end
+
+  class TestForRespondToFalse
+    def respond_to?(a)
+      false
+    end
+  end
+
+  def test_marshal_respond_to_arity
+    assert_nothing_raised(ArgumentError, '[Bug #7722]') do
+      Marshal.dump(TestForRespondToFalse.new)
+    end
+  end
 end
diff --git a/vm_method.c b/vm_method.c
index 2adc91d737..f2c361f521 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -1521,7 +1521,24 @@ rb_obj_respond_to(VALUE obj, ID id, int priv)
 	return basic_obj_respond_to(obj, id, !RTEST(priv));
     }
     else {
-	return RTEST(rb_funcall(obj, idRespond_to, priv ? 2 : 1, ID2SYM(id), Qtrue));
+	int argc = 1;
+	VALUE args[2];
+	args[0] = ID2SYM(id);
+	args[1] = Qtrue;
+	if (priv) {
+	    if (rb_obj_method_arity(obj, idRespond_to) != 1) {
+		argc = 2;
+	    }
+	    else {
+		VALUE klass = CLASS_OF(obj);
+		rb_warn("%"PRIsVALUE"%c""respond_to?(:%"PRIsVALUE") is"
+			" old fashion which takes only one parameter",
+			(FL_TEST(klass, FL_SINGLETON) ? obj : klass),
+			(FL_TEST(klass, FL_SINGLETON) ? '.' : '#'),
+			QUOTE_ID(id));
+	    }
+	}
+	return RTEST(rb_funcall2(obj, idRespond_to, argc,  args));
     }
 }