diff --git a/ChangeLog b/ChangeLog
index 9054db1642..e69b7e5ba9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,9 @@ Mon Oct  6 12:45:20 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 	* test/ruby/test_module.rb (TestModule#_wrap_assertion): add
 	  definition.  is this really needed?
 
+	* test/ruby/test_module.rb (TestModule#test_mod_constants): should
+	  not depend on global Module constants.
+
 Mon Oct  6 12:38:36 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* lib/test/unit/assertions.rb (Test::Assertions#assert_nothing_raised): 
diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index 17fbf56337..072f559c3c 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -544,10 +544,11 @@ class TestModule < Test::Unit::TestCase
   end
 
   def test_mod_constants
-    Module.const_set(:Foo, :foo)
-    assert_equal([:Foo], Module.constants(true))
-    assert_equal([:Foo], Module.constants(false))
-    Module.instance_eval { remove_const(:Foo) }
+    m = Module.new
+    m.const_set(:Foo, :foo)
+    assert_equal([:Foo], m.constants(true))
+    assert_equal([:Foo], m.constants(false))
+    m.instance_eval { remove_const(:Foo) }
   end
 
   def test_frozen_class