diff --git a/schematic.cabal b/schematic.cabal
--- a/schematic.cabal
+++ b/schematic.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                schematic
-version:             0.1.2.0
+version:             0.1.3.0
 synopsis:            JSON-biased spec and validation tool
 -- description:
 license:             BSD3
@@ -17,7 +17,6 @@
 
 library
   exposed-modules:     Data.Schematic
-                     -- , Data.Schematic.Class
                      , Data.Schematic.Instances
                      , Data.Schematic.Path
                      , Data.Schematic.Schema
diff --git a/src/Data/Schematic.hs b/src/Data/Schematic.hs
--- a/src/Data/Schematic.hs
+++ b/src/Data/Schematic.hs
@@ -70,7 +70,10 @@
     -> J.Value
     -> ParseResult (JsonRepr (Snd (Head revisions)))
 
-instance {-# OVERLAPPING #-} (TopLevel (Snd rev), SingI (Snd rev)) => Migratable '[rev] where
+instance
+  {-# OVERLAPPING #-}
+  ( TopLevel (Snd rev), SingI (Snd rev) )
+  => Migratable '[rev] where
   mparse _ = parseAndValidateJson
 
 instance {-# OVERLAPPABLE #-}
@@ -79,35 +82,10 @@
   , SingI (Snd (Head revisions)))
   => Migratable revisions where
   mparse s v = case parseEither parseJSON v of
-    Left _  -> migrate <$> mparse (sTail s) v
+    Left _  ->
+      migrate <$> (mparse (sTail s) v :: ParseResult (JsonRepr (Snd (Head (Tail revisions)))))
     Right x -> Valid x
--- type family Migratable (revisions :: [(Revision, Schema)]) = (cs :: Constraint) where
---   Migratable '[rev] = (TopLevel (Snd rev), SingI (Snd rev))
---   Migratable  revisions =
---    ( Migratable (Tail revisions)
---    , MigrateSchema (Snd (Head (Tail revisions))) (Snd (Head revisions))
---    , SingI (Snd (Head revisions)))
 
--- mparseBySing
---   :: Sing schema
---   -> J.Value
---   -> ParseResult (JsonRepr (Snd (Head revisions)))
--- mparseBySing s v = undefined
-
--- mparse
---   :: Migratable revisions
---   => Sing revisions
---   -> J.Value
---   -> ParseResult (JsonRepr (Snd (Head revisions)))
--- mparse s v =
---   let
---     st = sTail s
---     sth = sSnd $ sHead st
---   SCons x SNil -> parseAndValidateJson v
---   SCons sch _   -> case parseEither parseJSON v of
---     Left _  -> migrate <$> mparse (sTail s) v
---     Right x -> Valid x
-
 parseAndValidateVersionedJson
   :: forall proxy v. (SingI (AllVersions v), Migratable (AllVersions v))
   => proxy v
@@ -132,3 +110,8 @@
 decodeAndValidateVersionedJson vp bs = case decode bs of
   Nothing -> DecodingError "malformed json"
   Just x  -> parseAndValidateVersionedJson vp x
+
+decodeAndValidate
+  :: MList revisions
+  ->
+decodeAndValidate = undefined
diff --git a/test/SchemaSpec.hs b/test/SchemaSpec.hs
--- a/test/SchemaSpec.hs
+++ b/test/SchemaSpec.hs
@@ -8,6 +8,7 @@
 import Data.Proxy
 import Data.Schematic
 import Data.Singletons
+import Data.Singletons.Prelude
 import Data.Vinyl
 import Test.Hspec
 import Test.Hspec.SmallCheck
@@ -16,16 +17,17 @@
 
 
 type SchemaExample
-  = SchemaObject
-    '[ '("foo", SchemaArray '[AEq 1] (SchemaNumber '[NGt 10]))
-     , '("bar", SchemaOptional (SchemaText '[TEnum '["foo", "bar"]]))]
+  = 'SchemaObject
+    '[ '("foo", 'SchemaArray '[AEq 1] ('SchemaNumber '[NGt 10]))
+     , '("bar", 'SchemaOptional ('SchemaText '[TEnum '["foo", "bar"]]))]
 
-type VS =
-  'Versioned SchemaExample
-    '[ 'Migration "test_revision"
-       '[ 'Diff '[ 'PKey "bar" ] ('Update ('SchemaText '[]))
-        , 'Diff '[ 'PKey "foo" ] ('Update ('SchemaNumber '[])) ] ]
+type TestMigration =
+  'Migration "test_revision"
+    '[ 'Diff '[ 'PKey "bar" ] ('Update ('SchemaText '[]))
+     , 'Diff '[ 'PKey "foo" ] ('Update ('SchemaNumber '[])) ]
 
+type VS = 'Versioned SchemaExample '[ TestMigration ]
+
 exampleTest :: JsonRepr (SchemaOptional (SchemaText '[TEq 3]))
 exampleTest = ReprOptional (Just (ReprText "lil"))
 
@@ -50,6 +52,19 @@
 schemaJsonTopVersion :: ByteString
 schemaJsonTopVersion = "{ \"foo\": 42, \"bar\": \"bar\" }"
 
+instance
+     MigrateSchema
+       ('SchemaObject
+          '[ '("foo", 'SchemaArray '[ 'AEq 1] ('SchemaNumber '[ 'NGt 10 ])),
+             '("bar", 'SchemaOptional ('SchemaText '[ 'TEnum '["foo", "bar"]]))])
+       ('SchemaObject
+         '[ '("foo", 'SchemaNumber '[]), '("bar", 'SchemaText '[])])
+  where
+  migrate _ = ReprObject $
+    FieldRepr (ReprNumber 42)
+      :& FieldRepr (ReprText "test")
+      :& RNil
+
 spec :: Spec
 spec = do
   -- it "show/read JsonRepr properly" $
@@ -66,8 +81,9 @@
     ((decodeAndValidateJson schemaJson2) :: ParseResult (JsonRepr SchemaExample))
       `shouldSatisfy` isValidationError
   it "validates versioned json" $ do
-    (decodeAndValidateVersionedJson (Proxy @VS) schemaJsonTopVersion)
+    decodeAndValidateVersionedJson (Proxy @VS) schemaJson
       `shouldSatisfy` isValid
+
 
 main :: IO ()
 main = hspec spec