diff --git a/ext/-test-/notimplement/bug.c b/ext/-test-/notimplement/bug.c
index b8e871f55f..82e243a81d 100644
--- a/ext/-test-/notimplement/bug.c
+++ b/ext/-test-/notimplement/bug.c
@@ -11,7 +11,7 @@ void
 Init_notimplement(void)
 {
     VALUE mBug = rb_define_module("Bug");
-    VALUE klass = rb_define_module_under(mBug, "NotImplement");
+    VALUE klass = rb_define_class_under(mBug, "NotImplement", rb_cObject);
     rb_define_module_function(mBug, "funcall", bug_funcall, -1);
     rb_define_module_function(mBug, "notimplement", rb_f_notimplement, -1);
     rb_define_method(klass, "notimplement", rb_f_notimplement, -1);
diff --git a/test/-ext-/test_notimplement.rb b/test/-ext-/test_notimplement.rb
index 882c905faf..92a2fd22b8 100644
--- a/test/-ext-/test_notimplement.rb
+++ b/test/-ext-/test_notimplement.rb
@@ -7,10 +7,14 @@ class Test_NotImplement < Test::Unit::TestCase
     assert_raise(NotImplementedError, bug3662) {
       Bug.funcall(:notimplement)
     }
+    assert_raise(NotImplementedError) {
+      Bug::NotImplement.new.notimplement
+    }
   end
 
   def test_respond_to
     assert_not_respond_to(Bug, :notimplement)
+    assert_not_respond_to(Bug::NotImplement.new, :notimplement)
   end
 
   def test_not_method_defined