diff --git a/hspec-wai-json.cabal b/hspec-wai-json.cabal
--- a/hspec-wai-json.cabal
+++ b/hspec-wai-json.cabal
@@ -1,13 +1,21 @@
+-- This file has been generated from package.yml by hpack version 0.2.0.
+--
+-- see: https://github.com/sol/hpack
+
 name:             hspec-wai-json
-version:          0.6.0
+version:          0.6.1
+homepage:         https://github.com/hspec/hspec-wai#readme
+bug-reports:      https://github.com/hspec/hspec-wai/issues
 license:          MIT
 license-file:     LICENSE
 copyright:        (c) 2012-2014 Fujimura Daisuke,
                   (c) 2014 Simon Hengel
-author:           Fujimura Daisuke <me@fujimuradaisuke.com>, Simon Hengel <sol@typeful.net>
-maintainer:       Fujimura Daisuke <me@fujimuradaisuke.com>, Simon Hengel <sol@typeful.net>
+author:           Fujimura Daisuke <me@fujimuradaisuke.com>,
+                  Simon Hengel <sol@typeful.net>
+maintainer:       Fujimura Daisuke <me@fujimuradaisuke.com>,
+                  Simon Hengel <sol@typeful.net>
 build-type:       Simple
-cabal-version:    >= 1.8
+cabal-version:    >= 1.10
 category:         Testing
 synopsis:         Testing JSON APIs with hspec-wai
 description:      Testing JSON APIs with hspec-wai
@@ -17,10 +25,7 @@
   location: https://github.com/hspec/hspec-wai
 
 library
-  ghc-options:
-      -Wall
-  hs-source-dirs:
-      src
+  hs-source-dirs: src
   exposed-modules:
       Test.Hspec.Wai.JSON
   build-depends:
@@ -30,18 +35,20 @@
     , template-haskell
     , aeson
     , aeson-qq >= 0.7.3
+    , case-insensitive
+  ghc-options: -Wall
+  default-language: Haskell2010
 
 test-suite spec
-  type:
-      exitcode-stdio-1.0
-  ghc-options:
-      -Wall
-  hs-source-dirs:
-      test
-  main-is:
-      Spec.hs
+  type: exitcode-stdio-1.0
+  hs-source-dirs: test
+  main-is: Spec.hs
+  other-modules:
+      Test.Hspec.Wai.JSONSpec
   build-depends:
       base == 4.*
     , hspec-wai-json
     , hspec-wai
     , hspec
+  ghc-options: -Wall
+  default-language: Haskell2010
diff --git a/src/Test/Hspec/Wai/JSON.hs b/src/Test/Hspec/Wai/JSON.hs
--- a/src/Test/Hspec/Wai/JSON.hs
+++ b/src/Test/Hspec/Wai/JSON.hs
@@ -5,11 +5,13 @@
 , FromValue(..)
 ) where
 
+import           Control.Arrow (second)
 import           Data.List
 import           Data.ByteString.Lazy (ByteString)
 import qualified Data.ByteString.Lazy as BL
 import           Data.Aeson (Value, encode)
 import           Data.Aeson.QQ
+import qualified Data.CaseInsensitive as CI
 import           Language.Haskell.TH.Quote
 
 import           Test.Hspec.Wai
@@ -57,9 +59,14 @@
   fromValue v = ResponseMatcher 200 [MatchHeader p] (Just body)
     where
       body = fromValue v
+
       permissibleHeaders = addIfASCII ("Content-Type", "application/json") [("Content-Type", "application/json; charset=utf-8")]
+
       addIfASCII h = if BL.all (< 128) body then (h :) else id
-      p headers = if any (`elem` permissibleHeaders) headers
+
+      mkCI = map (second CI.mk)
+
+      p headers = if any (`elem` mkCI permissibleHeaders) (mkCI headers)
         then Nothing
         else (Just . unlines) ("missing header:" : (intersperse "  OR" $ map formatHeader permissibleHeaders))
 
diff --git a/test/Test/Hspec/Wai/JSONSpec.hs b/test/Test/Hspec/Wai/JSONSpec.hs
new file mode 100644
--- /dev/null
+++ b/test/Test/Hspec/Wai/JSONSpec.hs
@@ -0,0 +1,44 @@
+{-# LANGUAGE OverloadedStrings, QuasiQuotes #-}
+module Test.Hspec.Wai.JSONSpec (main, spec) where
+
+import           Test.Hspec
+
+import           Test.Hspec.Wai
+import           Test.Hspec.Wai.JSON
+
+main :: IO ()
+main = hspec spec
+
+spec :: Spec
+spec = do
+  describe "json" $ do
+    context "when matching Content-Type header" $ do
+      context "when JSON is ASCII" $ do
+        let [MatchHeader matcher] = matchHeaders [json|{foo: 23}|]
+        it "accepts 'application/json'" $ do
+          matcher [("Content-Type", "application/json")] `shouldBe` Nothing
+
+        it "accepts 'application/json; charset=utf-8'" $ do
+          matcher [("Content-Type", "application/json; charset=utf-8")] `shouldBe` Nothing
+
+        it "ignores case" $ do
+          matcher [("Content-Type", "application/JSON; charset=UTF-8")] `shouldBe` Nothing
+
+        it "rejects other headers" $ do
+          matcher [("Content-Type", "foobar")] `shouldBe` (Just . unlines) [
+              "missing header:"
+            , "  Content-Type: application/json"
+            , "  OR"
+            , "  Content-Type: application/json; charset=utf-8"
+            ]
+
+      context "when JSON contains Unicode" $ do
+        let [MatchHeader matcher] = matchHeaders [json|{foo: #{"\955" :: String}}|]
+        it "rejects 'application/json'" $ do
+          matcher [("Content-Type", "application/json")] `shouldBe` (Just . unlines) [
+              "missing header:"
+            , "  Content-Type: application/json; charset=utf-8"
+            ]
+
+        it "accepts 'application/json; charset=utf-8'" $ do
+          matcher [("Content-Type", "application/json; charset=utf-8")] `shouldBe` Nothing