diff --git a/ChangeLog b/ChangeLog
index ca9c71f9af..2b5c7f0b85 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Jan  3 23:56:28 2015  Ayumu AIZAWA  <ayumu.aizawa@gmail.com>
+
+	* hash.c: fix docs for Hash#invert. [ruby-core:66917] [Bug #10612]
+
 Sat Jan  3 19:52:12 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* include/ruby/intern.h (rb_str_new_literal): define on all
diff --git a/hash.c b/hash.c
index bd49a1dd92..d54ab8ada5 100644
--- a/hash.c
+++ b/hash.c
@@ -2093,6 +2093,8 @@ rb_hash_invert_i(VALUE key, VALUE value, VALUE hash)
  *
  *  Returns a new hash created by using <i>hsh</i>'s values as keys, and
  *  the keys as values.
+ *  If a key with the same value already exists in the <i>hsh</i>, then
+ *  the last one defined will be used, the earlier value(s) will be discarded.
  *
  *     h = { "n" => 100, "m" => 100, "y" => 300, "d" => 200, "a" => 0 }
  *     h.invert   #=> {0=>"a", 100=>"m", 200=>"d", 300=>"y"}