diff --git a/ChangeLog b/ChangeLog
index bbfc75eb3f..e6e2190bbb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Oct 18 14:40:32 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* numeric.c (num_sadded): remove newly defined singleton method
+	  that should not exist after exception handling.  [ruby-dev:36569]
+
 Sat Oct 18 13:30:53 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* string.c (rb_external_str_new): a new function to convert from
diff --git a/numeric.c b/numeric.c
index 06351eca31..042e0c306f 100644
--- a/numeric.c
+++ b/numeric.c
@@ -202,11 +202,13 @@ rb_num_coerce_relop(VALUE x, VALUE y, ID func)
 static VALUE
 num_sadded(VALUE x, VALUE name)
 {
+    const char *nstr = rb_id2name(rb_to_id(name));
     /* ruby_frame = ruby_frame->prev; */ /* pop frame for "singleton_method_added" */
     /* Numerics should be values; singleton_methods should not be added to them */
+    rb_remove_method(rb_singleton_class(x), nstr);
     rb_raise(rb_eTypeError,
 	     "can't define singleton method \"%s\" for %s",
-	     rb_id2name(rb_to_id(name)),
+	     nstr,
 	     rb_obj_classname(x));
     return Qnil;		/* not reached */
 }