diff --git a/ChangeLog b/ChangeLog
index ae21969894..35b8abf4ae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue May  3 23:25:48 2016  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
+
+	* numeric.c: [DOC] Update result of 123456789 ** -2.
+	  [ruby-dev:49606] [Bug #12339]
+
 Tue May  3 23:13:16 2016  Yuichiro Kaneko  <yui-knk@ruby-lang.org>
 
 	* internal.h (RCOMPLEX_SET_IMAG): undef RCOMPLEX_SET_IMAG
diff --git a/numeric.c b/numeric.c
index 4f43a754c7..29d5e250e2 100644
--- a/numeric.c
+++ b/numeric.c
@@ -3645,7 +3645,7 @@ int_divmod(VALUE x, VALUE y)
  *
  *    123456789 ** 2      #=> 15241578750190521
  *    123456789 ** 1.2    #=> 5126464716.09932
- *    123456789 ** -2     #=> 6.5610001194102e-17
+ *    123456789 ** -2     #=> (1/15241578750190521)
  *
  */