diff --git a/ChangeLog b/ChangeLog
index 748fe0bc88..87f828e792 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Sep  5 08:28:58 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* hash.c (rb_hash_equal, rb_hash_eql): [DOC] the orders of each
+	  hashes are not compared.  [Bug #11508]
+
 Fri Sep  4 23:26:22 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* include/ruby/win32.h: fix macro name for VC runtime version,
diff --git a/hash.c b/hash.c
index aecc68f1af..bc689a557f 100644
--- a/hash.c
+++ b/hash.c
@@ -2139,6 +2139,12 @@ hash_equal(VALUE hash1, VALUE hash2, int eql)
  *     h2 == h3   #=> true
  *     h3 == h4   #=> false
  *
+ *  The orders of each hashes are not compared.
+ *
+ *     h1 = { "a" => 1, "c" => 2 }
+ *     h2 = { "c" => 2, "a" => 1 }
+ *     h1 == h2   #=> true
+ *
  */
 
 static VALUE
@@ -2153,6 +2159,7 @@ rb_hash_equal(VALUE hash1, VALUE hash2)
  *
  *  Returns <code>true</code> if <i>hash</i> and <i>other</i> are
  *  both hashes with the same content.
+ *  The orders of each hashes are not compared.
  */
 
 static VALUE