1 files changed, 10 insertions, 2 deletions
diff --git a/activesupport/test/core_ext/duplicable_test.rb b/activesupport/test/core_ext/duplicable_test.rb
index d1a886fba0..356b849adf 100644
--- a/activesupport/test/core_ext/duplicable_test.rb
+++ b/activesupport/test/core_ext/duplicable_test.rb
@@ -4,17 +4,25 @@ require 'active_support/core_ext/object/duplicable'
 require 'active_support/core_ext/numeric/time'
 
 class DuplicableTest < Test::Unit::TestCase
-  RAISE_DUP  = [nil, false, true, :symbol, 1, 2.3, BigDecimal.new('4.56'), 5.seconds]
+  RAISE_DUP  = [nil, false, true, :symbol, 1, 2.3, 5.seconds]
   YES = ['1', Object.new, /foo/, [], {}, Time.now]
   NO = [Class.new, Module.new]
 
+  begin
+    bd = BigDecimal.new('4.56')
+    YES << bd.dup
+  rescue TypeError
+    RAISE_DUP << bd
+  end
+
+
   def test_duplicable
     (RAISE_DUP + NO).each do |v|
       assert !v.duplicable?
     end
 
     YES.each do |v|
-      assert v.duplicable?
+      assert v.duplicable?, "#{v.class} should be duplicable"
     end
 
     (YES + NO).each do |v|