diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2016 Tom Sydney Kerckhove
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/genvalidity-hspec-aeson.cabal b/genvalidity-hspec-aeson.cabal
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--- /dev/null
+++ b/genvalidity-hspec-aeson.cabal
@@ -0,0 +1,57 @@
+name: genvalidity-hspec-aeson
+version: 0.0.0.0
+synopsis: Standard spec's for aeson-related instances
+description: Standard spec's for aeson-related Instances
+cabal-version: >=1.10
+build-type: Simple
+license: MIT
+license-file: LICENSE
+copyright: Copyright: (c) 2016 Tom Sydney Kerckhove
+maintainer: syd.kerckhove@gmail.com
+homepage: http://cs-syd.eu
+category: Testing
+author: Tom Sydney Kerckhove
+
+library
+    exposed-modules:
+        Test.Validity.Aeson
+    build-depends:
+        base >=4.9 && <=5,
+        genvalidity-hspec >= 0.3 && < 0.4,
+        genvalidity >= 0.3 && < 0.4,
+        hspec >= 2.2 && < 2.3,
+        aeson >= 0.11 && < 0.12,
+        QuickCheck >= 2.8 && < 2.9,
+        deepseq >= 1.4 && < 1.5
+    default-language: Haskell2010
+    hs-source-dirs: src/
+    ghc-options: -Wall
+
+test-suite genvalidity-hspec-aeson-doctests
+  default-language:   Haskell2010
+  hs-source-dirs:     test
+  type:               exitcode-stdio-1.0
+  ghc-options:        -threaded
+  main-is:            DocTest.hs
+  build-depends:      base
+    , doctest               >= 0.11      && < 0.12
+    , genvalidity-hspec-aeson
+
+test-suite genvalidity-hspec-aeson-test
+    type: exitcode-stdio-1.0
+    main-is: Spec.hs
+    other-modules:
+        Test.Validity.AesonSpec
+    build-depends:
+        base >=4.9 && <=5,
+        genvalidity >= 0.3 && < 0.4,
+        genvalidity-hspec-aeson,
+        hspec >= 2.2 && < 2.3
+    default-language: Haskell2010
+    hs-source-dirs: test/
+    ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall
+
+
+source-repository head
+  type:     git
+  location: https://github.com/NorfairKing/validity
diff --git a/src/Test/Validity/Aeson.hs b/src/Test/Validity/Aeson.hs
new file mode 100644
--- /dev/null
+++ b/src/Test/Validity/Aeson.hs
@@ -0,0 +1,115 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE AllowAmbiguousTypes #-}
+
+-- | Standard test `Spec`s and raw `Property`s for `FromJSON` and `ToJSON` instances.
+--
+-- You will need @TypeApplications@ to use these.
+module Test.Validity.Aeson
+    ( jsonSpecOnValid
+    , jsonSpec
+    , jsonSpecOnArbitrary
+    , jsonSpecOnGen
+    , neverFailsToEncodeOnGen
+    , encodeAndDecodeAreInversesOnGen
+    ) where
+
+import Data.GenValidity
+
+import Control.DeepSeq (deepseq)
+import Control.Exception (evaluate)
+import Data.Aeson (FromJSON, ToJSON)
+import qualified Data.Aeson as JSON
+import Data.Typeable
+import Test.Hspec
+import Test.QuickCheck
+import Test.Validity.Utils
+
+-- | Standard test spec for properties of JSON-related functions for valid values
+--
+-- Example usage:
+--
+-- > jsonSpecOnValid @Double
+jsonSpecOnValid
+    :: forall a.
+       (Show a, Eq a, Typeable a, GenValid a, FromJSON a, ToJSON a)
+    => Spec
+jsonSpecOnValid = jsonSpecOnGen (genValid @a) "valid"
+
+-- | Standard test spec for properties of JSON-related functions for unchecked values
+--
+-- Example usage:
+--
+-- > jsonSpec @Int
+jsonSpec
+    :: forall a.
+       (Show a, Eq a, Typeable a, GenUnchecked a, FromJSON a, ToJSON a)
+    => Spec
+jsonSpec = jsonSpecOnGen (genUnchecked @a) "unchecked"
+
+-- | Standard test spec for properties of JSON-related functions for arbitrary values
+--
+-- Example usage:
+--
+-- > jsonSpecOnArbitrary @Int
+jsonSpecOnArbitrary
+    :: forall a.
+       (Show a, Eq a, Typeable a, Arbitrary a, FromJSON a, ToJSON a)
+    => Spec
+jsonSpecOnArbitrary = jsonSpecOnGen (arbitrary @a) "arbitrary"
+
+-- | Standard test spec for properties of JSON-related functions for a given generator (and a name for that generator).
+--
+-- Example usage:
+--
+-- > jsonSpecOnGen (genListOf $ pure 'a') "sequence of 'a's"
+jsonSpecOnGen
+    :: forall a.
+       (Show a, Eq a, Typeable a, FromJSON a, ToJSON a)
+    => Gen a -> String -> Spec
+jsonSpecOnGen gen genname = parallel $ do
+    let name = nameOf @a
+    describe ("JSON " ++ name ++ " (" ++ genname ++ ")") $ do
+        describe ("encode :: " ++ name ++ " -> Data.ByteString.Lazy.ByteString") $
+            it
+                (unwords
+                     ["never fails to encode a", "\"" ++ genname, name ++ "\""]) $
+            neverFailsToEncodeOnGen gen
+        describe ("decode :: " ++ name ++ " -> Data.ByteString.Lazy.ByteString") $
+            it
+                (unwords
+                     [ "ensures that encode and decode are inverses for"
+                     , "\"" ++ genname
+                     , name ++ "\"" ++ "'s"
+                     ]) $
+            encodeAndDecodeAreInversesOnGen gen
+
+-- |
+--
+-- prop> neverFailsToEncodeOnGen @Bool arbitrary
+-- prop> neverFailsToEncodeOnGen @Bool genUnchecked
+-- prop> neverFailsToEncodeOnGen @Bool genValid
+-- prop> neverFailsToEncodeOnGen @Int arbitrary
+-- prop> neverFailsToEncodeOnGen @Int genUnchecked
+-- prop> neverFailsToEncodeOnGen @Int genValid
+neverFailsToEncodeOnGen
+    :: (Show a, ToJSON a)
+    => Gen a -> Property
+neverFailsToEncodeOnGen gen =
+    forAll gen $ \(a :: a) ->
+        evaluate (deepseq (JSON.encode a) ()) `shouldReturn` ()
+
+-- |
+--
+-- prop> encodeAndDecodeAreInversesOnGen @Bool arbitrary
+-- prop> encodeAndDecodeAreInversesOnGen @Bool genUnchecked
+-- prop> encodeAndDecodeAreInversesOnGen @Bool genValid
+-- prop> encodeAndDecodeAreInversesOnGen @Int arbitrary
+-- prop> encodeAndDecodeAreInversesOnGen @Int genUnchecked
+-- prop> encodeAndDecodeAreInversesOnGen @Int genValid
+encodeAndDecodeAreInversesOnGen
+    :: (Show a, Eq a, FromJSON a, ToJSON a)
+    => Gen a -> Property
+encodeAndDecodeAreInversesOnGen gen =
+    forAll gen $ \(a :: a) ->
+        JSON.eitherDecode (JSON.encode a) `shouldBe` Right a
diff --git a/test/DocTest.hs b/test/DocTest.hs
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--- /dev/null
+++ b/test/DocTest.hs
@@ -0,0 +1,4 @@
+import Test.DocTest
+
+main :: IO ()
+main = doctest ["-isrc", "src", "-XTypeApplications"]
diff --git a/test/Spec.hs b/test/Spec.hs
new file mode 100644
--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,1 @@
+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}
diff --git a/test/Test/Validity/AesonSpec.hs b/test/Test/Validity/AesonSpec.hs
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--- /dev/null
+++ b/test/Test/Validity/AesonSpec.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE TypeApplications #-}
+
+module Test.Validity.AesonSpec where
+
+import Test.Hspec
+
+import Data.GenValidity
+import Test.Validity.Aeson
+
+spec :: Spec
+spec = do
+    jsonSpecOnGen (genListOf $ pure 'a') "sequence of 'a's"
+    jsonSpecOnValid @Double
+    jsonSpec @Int
+    jsonSpecOnArbitrary @Int