diff --git a/ChangeLog b/ChangeLog
index 0b43453147..a3a25a7a6f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Mon Dec 29 21:22:31 2008  Tadayoshi Funaba  <tadf@dotrb.org>
+
+	* numeric.c: Infinity.numerator returns self. [experimental]
+
+	* numeric.c: Infinity.denominator returns 1. [experimental]
+
 Mon Dec 29 20:57:14 2008  Yuki Sonoda (Yugui)  <yugui@yugui.jp>
 
 	* man/ri.1: new manpage.
diff --git a/numeric.c b/numeric.c
index e18333c0e4..483c330bce 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1352,6 +1352,23 @@ flo_truncate(VALUE num)
     return LONG2FIX(val);
 }
 
+static VALUE
+flo_numerator(VALUE num)
+{
+    double d = RFLOAT_VALUE(num);
+    if (isinf(d) || isnan(d))
+	return num;
+    return rb_call_super(0, 0);
+}
+
+static VALUE
+flo_denominator(VALUE num)
+{
+    double d = RFLOAT_VALUE(num);
+    if (isinf(d) || isnan(d))
+	return INT2FIX(1);
+    return rb_call_super(0, 0);
+}
 
 /*
  *  call-seq:
@@ -3247,6 +3264,9 @@ Init_Numeric(void)
     rb_define_method(rb_cFloat, "round", flo_round, -1);
     rb_define_method(rb_cFloat, "truncate", flo_truncate, 0);
 
+    rb_define_method(rb_cFloat, "numerator", flo_numerator, 0);
+    rb_define_method(rb_cFloat, "denominator", flo_denominator, 0);
+
     rb_define_method(rb_cFloat, "nan?",      flo_is_nan_p, 0);
     rb_define_method(rb_cFloat, "infinite?", flo_is_infinite_p, 0);
     rb_define_method(rb_cFloat, "finite?",   flo_is_finite_p, 0);