diff --git a/ChangeLog b/ChangeLog
index 1d546a921b..e126f1378f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jun 29 16:01:24 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
+
 Mon Jun 29 14:50:08 2015  Shugo Maeda  <shugo@ruby-lang.org>
 
 	* eval.c (add_activated_refinement): should not include the original
diff --git a/lib/net/http/response.rb b/lib/net/http/response.rb
index b0731694ca..219e14e777 100644
--- a/lib/net/http/response.rb
+++ b/lib/net/http/response.rb
@@ -250,7 +250,7 @@ class Net::HTTPResponse
     return yield @socket unless @decode_content
     return yield @socket if self['content-range']
 
-    case self['content-encoding']
+    case self['content-encoding'].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 ba8b45eaca..7d378648b3 100644
--- a/test/net/http/test_httpresponse.rb
+++ b/test/net/http/test_httpresponse.rb
@@ -82,6 +82,34 @@ 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_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