diff --git a/ChangeLog b/ChangeLog
index 2e69e76760..3e65cfc45d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Jul 11 23:05:40 2008  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* test/zlib/test_zlib.rb: add a test for Zlib::Deflate#params.
+
 Fri Jul 11 22:58:28 2008  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* ext/zlib/zlib.c (rb_deflate_params): flush before deflateParams.
diff --git a/test/zlib/test_zlib.rb b/test/zlib/test_zlib.rb
index dcbcb21ea8..5264306bc2 100644
--- a/test/zlib/test_zlib.rb
+++ b/test/zlib/test_zlib.rb
@@ -120,6 +120,14 @@ if defined? Zlib
       s = z.finish
       assert_equal("foobar", Zlib::Inflate.inflate(s))
 
+      data = ('a'..'z').to_a.join
+      z = Zlib::Deflate.new(Zlib::NO_COMPRESSION, Zlib::MAX_WBITS,
+                            Zlib::DEF_MEM_LEVEL, Zlib::DEFAULT_STRATEGY)
+      z << data[0, 10]
+      z.params(Zlib::BEST_COMPRESSION, Zlib::DEFAULT_STRATEGY)
+      z << data[10 .. -1]
+      assert_equal(data, Zlib::Inflate.inflate(z.finish))
+
       z = Zlib::Deflate.new
       s = z.deflate("foo", Zlib::FULL_FLUSH)
       z.avail_out = 0