diff --git a/ChangeLog b/ChangeLog
index 592208f1c1..a57bed1b69 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Dec  4 19:16:39 2006  Akinori MUSHA  <knu@iDaemons.org>
+
+	* ext/digest/lib/digest/hmac.rb: Do alias << update.
+
 Mon Dec  4 10:48:03 2006  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* ruby.h (OFFT2NUM): use LONG2NUM() if sizeof(long) equals to
diff --git a/ext/digest/lib/digest/hmac.rb b/ext/digest/lib/digest/hmac.rb
index a0cc948a6c..cdd537689c 100644
--- a/ext/digest/lib/digest/hmac.rb
+++ b/ext/digest/lib/digest/hmac.rb
@@ -71,6 +71,7 @@ module Digest
       @md.update(text)
       self
     end
+    alias << update
 
     def reset
       @md.reset