diff --git a/ChangeLog b/ChangeLog
index 374c8247cc..b1483efbe6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Jun 27 16:56:33 2009  Tadayoshi Funaba  <tadf@dotrb.org>
+
+	* rational.c (nurat_cmp): use rb_num_coerce_cmp.
+
 Sat Jun 27 16:45:10 2009  Tadayoshi Funaba  <tadf@dotrb.org>
 
 	* complex.c: revised rdoc.
diff --git a/rational.c b/rational.c
index 218a14883c..5a490d48c7 100644
--- a/rational.c
+++ b/rational.c
@@ -979,7 +979,7 @@ nurat_cmp(VALUE self, VALUE other)
 	    return f_cmp(f_sub(num1, num2), ZERO);
 	}
       default:
-	return rb_num_coerce_bin(self, other, id_cmp);
+	return rb_num_coerce_cmp(self, other, id_cmp);
     }
 }
 
diff --git a/test/ruby/test_rational.rb b/test/ruby/test_rational.rb
index b43db9c982..bbea2da83c 100644
--- a/test/ruby/test_rational.rb
+++ b/test/ruby/test_rational.rb
@@ -692,6 +692,9 @@ class Rational_Test < Test::Unit::TestCase
     assert_equal(true, Rational(0) <= Rational(0))
     assert_equal(true, Rational(0) >= Rational(0))
     assert_equal(false, Rational(0) > Rational(0))
+
+    assert_equal(nil, Rational(0) <=> nil)
+    assert_equal(nil, Rational(0) <=> 'foo')
   end
 
   def test_equal