diff --git a/ChangeLog b/ChangeLog
index bd0dc77809..5a7907ea07 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Aug 31 14:51:27 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* test/bigdecimal/test_bigdecimal.rb (TestBigDecimal#test_to_f): added
+	  for previous commit.
+
 Fri Aug 31 14:32:05 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* ext/bigdecimal/bigdecimal.c (BigDecimal_to_f): use self's sign to
diff --git a/test/bigdecimal/test_bigdecimal.rb b/test/bigdecimal/test_bigdecimal.rb
index 6694697e0e..856281d046 100644
--- a/test/bigdecimal/test_bigdecimal.rb
+++ b/test/bigdecimal/test_bigdecimal.rb
@@ -569,6 +569,11 @@ class TestBigDecimal < Test::Unit::TestCase
     assert_nothing_raised(FloatDomainError, x) {
       assert_in_delta(0.0, BigDecimal(x).to_f, 10**Float::MIN_10_EXP, bug6944)
     }
+
+    assert_equal( 0.0, BigDecimal(  '9e-325').to_f)
+    assert_equal( 0.0, BigDecimal( '10e-325').to_f)
+    assert_equal(-0.0, BigDecimal( '-9e-325').to_f)
+    assert_equal(-0.0, BigDecimal('-10e-325').to_f)
   end
 
   def test_coerce