diff --git a/ChangeLog b/ChangeLog
index d5361b02a3..280a60dc72 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Wed Nov  7 03:45:12 2012  Luis Lavena  <luislavena@gmail.com>
+
+	* ext/zlib/extconf.rb: Recognize zlibwapi as linking library.
+	  Patch by Daniel Berger.
+
+	  [ruby-core:44979] [Feature #6421]
+
 Wed Nov  7 02:06:40 2012  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
 
 	* enumerator.c: New method #size; constructor accepts size.
diff --git a/ext/zlib/extconf.rb b/ext/zlib/extconf.rb
index c49c29d463..b4348ceca7 100644
--- a/ext/zlib/extconf.rb
+++ b/ext/zlib/extconf.rb
@@ -10,7 +10,7 @@ require 'rbconfig'
 dir_config 'zlib'
 
 
-if %w'z libz zlib1 zlib zdll'.find {|z| have_library(z, 'deflateReset')} and
+if %w'z libz zlib1 zlib zdll zlibwapi'.find {|z| have_library(z, 'deflateReset')} and
     have_header('zlib.h') then
 
   defines = []