diff --git a/ChangeLog b/ChangeLog
index 4599552673..680c6b7e19 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+Tue Aug 11 01:37:28 2015  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
+
+	* test/net/http/test_httpresponse.rb
+	(HTTPResponseTest#test_read_body_content_encoding_deflate_uppercase):
+	fix a failure without zlib.
+
+Tue Aug 11 01:37:28 2015  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* lib/net/http/response.rb (inflater): CONTENT_ENCODING can be upper
+	  case. [ruby-core:69670] [Bug #11285] patched by Andy Chu
+
 Tue Aug 11 01:21:49 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* vm.c (m_core_hash_merge_ptr): copy the arguments to the machine
diff --git a/lib/net/http/response.rb b/lib/net/http/response.rb
index b0731694ca..674faf2cfc 100644
--- a/lib/net/http/response.rb
+++ b/lib/net/http/response.rb
@@ -250,7 +250,8 @@ class Net::HTTPResponse
     return yield @socket unless @decode_content
     return yield @socket if self['content-range']
 
-    case self['content-encoding']
+    v = self['content-encoding']
+    case v && v.downcase
     when 'deflate', 'gzip', 'x-gzip' then
       self.delete 'content-encoding'
 
diff --git a/test/net/http/test_httpresponse.rb b/test/net/http/test_httpresponse.rb
index 0193a153e4..a9cd9f5d26 100644
--- a/test/net/http/test_httpresponse.rb
+++ b/test/net/http/test_httpresponse.rb
@@ -103,6 +103,34 @@ EOS
     end
   end
 
+  def test_read_body_content_encoding_deflate_uppercase
+    io = dummy_io(<<EOS)
+HTTP/1.1 200 OK
+Connection: close
+Content-Encoding: DEFLATE
+Content-Length: 13
+
+x\x9C\xCBH\xCD\xC9\xC9\a\x00\x06,\x02\x15
+EOS
+
+    res = Net::HTTPResponse.read_new(io)
+    res.decode_content = true
+
+    body = nil
+
+    res.reading_body io, true do
+      body = res.read_body
+    end
+
+    if Net::HTTP::HAVE_ZLIB
+      assert_equal nil, res['content-encoding']
+      assert_equal 'hello', body
+    else
+      assert_equal 'DEFLATE', res['content-encoding']
+      assert_equal "x\x9C\xCBH\xCD\xC9\xC9\a\x00\x06,\x02\x15", body
+    end
+  end
+
   def test_read_body_content_encoding_deflate_chunked
     io = dummy_io(<<EOS)
 HTTP/1.1 200 OK
diff --git a/version.h b/version.h
index d54887f2d8..ee666b3057 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.2.3"
 #define RUBY_RELEASE_DATE "2015-08-11"
-#define RUBY_PATCHLEVEL 154
+#define RUBY_PATCHLEVEL 155
 
 #define RUBY_RELEASE_YEAR 2015
 #define RUBY_RELEASE_MONTH 8