diff --git a/ChangeLog b/ChangeLog
index 12031a53c0..b80d6a0826 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat May  5 01:47:33 2012  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* test/zlib/test_zlib.rb (test_inflate): add a test for Zlib.inflate.
+	  patched by headius (Charles Nutter). [ruby-core:44859] [Bug #6398]
+
+	* test/zlib/test_zlib.rb (test_deflate): add a test for Zlib.deflate.
+
 Sat May  5 00:53:55 2012  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* io.c (parse_mode_enc): remove warnings 'Ignoring internal encoding'.
diff --git a/test/zlib/test_zlib.rb b/test/zlib/test_zlib.rb
index 1e3d77160c..699b65a5f4 100644
--- a/test/zlib/test_zlib.rb
+++ b/test/zlib/test_zlib.rb
@@ -869,5 +869,13 @@ if defined? Zlib
       assert_instance_of(Array, t)
       t.each {|x| assert_kind_of(Integer, x) }
     end
+
+    def test_inflate
+      TestZlibInflate.new(__name__).test_inflate
+    end
+
+    def test_deflate
+      TestZlibDeflate.new(__name__).test_deflate
+    end
   end
 end