diff --git a/lib/hs/test/JSONSpec.hs b/lib/hs/test/JSONSpec.hs
new file mode 100644
index 0000000..079be02
--- /dev/null
+++ b/lib/hs/test/JSONSpec.hs
@@ -0,0 +1,195 @@
+--
+-- Licensed to the Apache Software Foundation (ASF) under one
+-- or more contributor license agreements. See the NOTICE file
+-- distributed with this work for additional information
+-- regarding copyright ownership. The ASF licenses this file
+-- to you under the Apache License, Version 2.0 (the
+-- "License"); you may not use this file except in compliance
+-- with the License. You may obtain a copy of the License at
+--
+--   http://www.apache.org/licenses/LICENSE-2.0
+--
+-- Unless required by applicable law or agreed to in writing,
+-- software distributed under the License is distributed on an
+-- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+-- KIND, either express or implied. See the License for the
+-- specific language governing permissions and limitations
+-- under the License.
+--
+
+module JSONSpec where
+
+import Test.Hspec
+import Test.Hspec.QuickCheck (prop)
+
+import qualified Data.ByteString.Lazy.Char8 as C
+
+import Thrift.Types
+import Thrift.Transport
+import Thrift.Transport.Memory
+import Thrift.Protocol
+import Thrift.Protocol.JSON
+
+tString :: [Char] -> ThriftVal
+tString = TString . C.pack
+
+spec :: Spec
+spec = do
+  describe "JSONProtocol" $ do
+    describe "bool" $ do
+      it "writes true as 1" $ do
+        let val = True
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto (TBool val)
+        bin <-tRead trans 100
+        (C.unpack bin) `shouldBe` ['1']
+
+      it "writes false as 0" $ do
+        let val = False
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto (TBool val)
+        bin <- tRead trans 100
+        (C.unpack bin) `shouldBe` ['0']
+
+      prop "round trip" $ \val -> do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto $ TBool val
+        val2 <- readVal proto T_BOOL
+        val2 `shouldBe` (TBool val)
+
+    describe "string" $ do
+      it "writes" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto (TString $ C.pack "\"a")
+        bin <- tRead trans 100
+        (C.unpack bin) `shouldBe` "\"\\\"a\""
+
+      it "reads" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        tWrite trans $ C.pack "\"\\\"a\""
+        val <- readVal proto (T_STRING)
+        val `shouldBe` (TString $ C.pack "\"a")
+
+      prop "round trip" $ \val -> do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto (TString $ C.pack val)
+        val2 <- readVal proto (T_STRING)
+        val2 `shouldBe` (TString $ C.pack val)
+
+    describe "list" $ do
+      it "writes empty list" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto (TList T_BYTE [])
+        bin <- tRead trans 100
+        (C.unpack bin) `shouldBe` "[\"i8\",0]"
+
+      it "reads empty" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        tWrite trans (C.pack "[\"i8\",0]")
+        val <- readVal proto (T_LIST T_BYTE)
+        val `shouldBe` (TList T_BYTE [])
+
+      it "writes single element" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto (TList T_BYTE [TByte 0])
+        bin <- tRead trans 100
+        (C.unpack bin) `shouldBe` "[\"i8\",1,0]"
+
+      it "reads single element" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        tWrite trans (C.pack "[\"i8\",1,0]")
+        val <- readVal proto (T_LIST T_BYTE)
+        val `shouldBe` (TList T_BYTE [TByte 0])
+
+      it "reads elements" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        tWrite trans (C.pack "[\"i8\",2,42, 43]")
+        val <- readVal proto (T_LIST T_BYTE)
+        val `shouldBe` (TList T_BYTE [TByte 42, TByte 43])
+
+      prop "round trip" $ \val -> do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto $ (TList T_STRING $ map tString val)
+        val2 <- readVal proto $ T_LIST T_STRING
+        val2 `shouldBe` (TList T_STRING $ map tString val)
+
+    describe "set" $ do
+      it "writes empty" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto (TSet T_BYTE [])
+        bin <- tRead trans 100
+        (C.unpack bin) `shouldBe` "[\"i8\",0]"
+
+      it "reads empty" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        tWrite trans (C.pack "[\"i8\",0]")
+        val <- readVal proto (T_SET T_BYTE)
+        val `shouldBe` (TSet T_BYTE [])
+
+      it "reads single element" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        tWrite trans (C.pack "[\"i8\",1,0]")
+        val <- readVal proto (T_SET T_BYTE)
+        val `shouldBe` (TSet T_BYTE [TByte 0])
+
+      it "reads elements" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        tWrite trans (C.pack "[\"i8\",2,42, 43]")
+        val <- readVal proto (T_SET T_BYTE)
+        val `shouldBe` (TSet T_BYTE [TByte 42, TByte 43])
+
+      prop "round trip" $ \val -> do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto $ (TSet T_STRING $ map tString val)
+        val2 <- readVal proto $ T_SET T_STRING
+        val2 `shouldBe` (TSet T_STRING $ map tString val)
+
+    describe "map" $ do
+      it "writes empty" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto (TMap T_BYTE T_BYTE [])
+        bin <- tRead trans 100
+        (C.unpack bin) `shouldBe`"[\"i8\",\"i8\",0,{}]"
+
+      it "reads empty" $ do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        tWrite trans (C.pack "[\"i8\",\"i8\",0,{}]")
+        val <- readVal proto (T_MAP T_BYTE T_BYTE)
+        val `shouldBe` (TMap T_BYTE T_BYTE [])
+
+      it "reads string-string" $ do
+        let bin = "[\"str\",\"str\",2,{\"a\":\"2\",\"b\":\"blah\"}]"
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        tWrite trans (C.pack bin)
+        val <- readVal proto (T_MAP T_STRING T_STRING)
+        val`shouldBe` (TMap T_STRING T_STRING [(tString "a", tString "2"), (tString "b", tString "blah")])
+
+      prop "round trip" $ \val -> do
+        trans <- openMemoryBuffer
+        let proto = JSONProtocol trans
+        writeVal proto $ (TMap T_STRING T_STRING $ map toKV val)
+        val2 <- readVal proto $ T_MAP T_STRING T_STRING
+        val2 `shouldBe` (TMap T_STRING T_STRING $ map toKV val)
+        where
+          toKV v = (tString v, tString v)
+
diff --git a/lib/hs/test/Spec.hs b/lib/hs/test/Spec.hs
index 0f5a816..7ec9a99 100644
--- a/lib/hs/test/Spec.hs
+++ b/lib/hs/test/Spec.hs
@@ -26,6 +26,7 @@
 
 import qualified BinarySpec
 import qualified CompactSpec
+import qualified JSONSpec
 
 main :: IO ()
 main = hspec spec
@@ -34,3 +35,4 @@
 spec = do
   describe "Binary" BinarySpec.spec
   describe "Compact" CompactSpec.spec
+  describe "JSON" JSONSpec.spec