diff --git a/autodocodec-yaml.cabal b/autodocodec-yaml.cabal
--- a/autodocodec-yaml.cabal
+++ b/autodocodec-yaml.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           autodocodec-yaml
-version:        0.3.0.0
+version:        0.3.0.1
 synopsis:       Autodocodec interpreters for yaml
 homepage:       https://github.com/NorfairKing/autodocodec#readme
 bug-reports:    https://github.com/NorfairKing/autodocodec/issues
@@ -34,8 +34,8 @@
   hs-source-dirs:
       src
   build-depends:
-      autodocodec >=0.2.3.0
-    , autodocodec-schema >=0.1.0.0
+      autodocodec >=0.3.0.0
+    , autodocodec-schema >=0.1.0.5
     , base >=4.7 && <5
     , bytestring
     , containers
diff --git a/src/Autodocodec/Yaml/Encode.hs b/src/Autodocodec/Yaml/Encode.hs
--- a/src/Autodocodec/Yaml/Encode.hs
+++ b/src/Autodocodec/Yaml/Encode.hs
@@ -12,6 +12,7 @@
 import Autodocodec.Codec
 import Autodocodec.DerivingVia
 import Control.Arrow (first)
+import Data.Coerce (coerce)
 import Data.Scientific
 import Data.Text (Text)
 import qualified Data.Text as T
@@ -33,17 +34,17 @@
     go :: a -> ValueCodec a void -> YamlBuilder
     go a = \case
       NullCodec -> Yaml.null
-      BoolCodec _ -> Yaml.bool (a :: Bool)
-      StringCodec _ -> Yaml.string (a :: Text)
-      NumberCodec _ _ -> yamlNumber (a :: Scientific)
-      ArrayOfCodec _ c -> Yaml.array (map (`go` c) (V.toList (a :: Vector _)))
+      BoolCodec _ -> Yaml.bool (coerce a :: Bool)
+      StringCodec _ -> Yaml.string (coerce a :: Text)
+      NumberCodec _ _ -> yamlNumber (coerce a :: Scientific)
+      ArrayOfCodec _ c -> Yaml.array (map (`go` c) (V.toList (coerce a :: Vector _)))
       ObjectOfCodec _ oc -> Yaml.mapping (goObject a oc)
-      HashMapCodec c -> go (toJSONVia (HashMapCodec c) a) ValueCodec -- This may be optimisable?
-      MapCodec c -> go (toJSONVia (MapCodec c) a) ValueCodec -- This may be optimisable?
-      ValueCodec -> yamlValue (a :: JSON.Value)
+      c@(HashMapCodec {}) -> go (toJSONVia c a) valueCodec -- This may be optimisable?
+      c@(MapCodec {}) -> go (toJSONVia c a) valueCodec -- This may be optimisable?
+      ValueCodec -> yamlValue (coerce a :: JSON.Value)
       EqCodec value c -> go value c
       BimapCodec _ g c -> go (g a) c
-      EitherCodec _ c1 c2 -> case (a :: Either _ _) of
+      EitherCodec _ c1 c2 -> case (coerce a :: Either _ _) of
         Left a1 -> go a1 c1
         Right a2 -> go a2 c2
       CommentCodec _ c -> go a c
@@ -52,16 +53,16 @@
     goObject :: a -> ObjectCodec a void -> [(Text, YamlBuilder)]
     goObject a = \case
       RequiredKeyCodec k c _ -> [(k, go a c)]
-      OptionalKeyCodec k c _ -> case (a :: Maybe _) of
+      OptionalKeyCodec k c _ -> case (coerce a :: Maybe _) of
         Nothing -> []
         Just b -> [k Yaml..= go b c]
-      OptionalKeyWithDefaultCodec k c _ mDoc -> goObject (Just a) (OptionalKeyCodec k c mDoc)
+      OptionalKeyWithDefaultCodec k c _ mDoc -> goObject (Just a) (optionalKeyCodec k c mDoc)
       OptionalKeyWithOmittedDefaultCodec k c defaultValue mDoc ->
-        if a == defaultValue
+        if coerce a == defaultValue
           then []
-          else goObject a (OptionalKeyWithDefaultCodec k c defaultValue mDoc)
+          else goObject a (optionalKeyWithDefaultCodec k (coerce c) (coerce defaultValue) mDoc)
       BimapCodec _ g c -> goObject (g a) c
-      EitherCodec _ c1 c2 -> case (a :: Either _ _) of
+      EitherCodec _ c1 c2 -> case (coerce a :: Either _ _) of
         Left a1 -> goObject a1 c1
         Right a2 -> goObject a2 c2
       DiscriminatedUnionCodec propertyName m _ ->
diff --git a/src/Autodocodec/Yaml/Schema.hs b/src/Autodocodec/Yaml/Schema.hs
--- a/src/Autodocodec/Yaml/Schema.hs
+++ b/src/Autodocodec/Yaml/Schema.hs
@@ -1,8 +1,6 @@
 {-# LANGUAGE AllowAmbiguousTypes #-}
 {-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE MultiWayIf #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeApplications #-}
 
@@ -23,12 +21,10 @@
 import Data.List.NonEmpty (NonEmpty (..))
 import qualified Data.List.NonEmpty as NE
 import qualified Data.Map as M
-import Data.Scientific (Scientific, floatingOrInteger)
 import Data.Text (Text)
 import qualified Data.Text as T
 import qualified Data.Text.Encoding as TE
 import qualified Data.Text.Encoding.Error as TE
-import Data.Word
 import Data.Yaml as Yaml
 import Text.Colour
 
@@ -173,40 +169,3 @@
           MinusPowerOf2MinusOne w -> chunk $ T.pack $ "- (2^" <> show w <> "-1)"
           OtherInteger i -> chunk $ T.pack $ show i
           OtherDouble d -> chunk $ T.pack $ show d
-
-data NumberBoundsSymbolic
-  = BitUInt !Word8 -- w bit unsigned int
-  | BitSInt !Word8 -- w bit signed int
-  | OtherNumberBounds !ScientificSymbolic !ScientificSymbolic
-
-guessNumberBoundsSymbolic :: NumberBounds -> NumberBoundsSymbolic
-guessNumberBoundsSymbolic NumberBounds {..} =
-  case (guessScientificSymbolic numberBoundsLower, guessScientificSymbolic numberBoundsUpper) of
-    (Zero, PowerOf2MinusOne w) -> BitUInt w
-    (MinusPowerOf2 w1, PowerOf2MinusOne w2) | w1 == w2 -> BitSInt (succ w1)
-    (l, u) -> OtherNumberBounds l u
-
-data ScientificSymbolic
-  = Zero
-  | PowerOf2 !Word8 -- 2^w
-  | PowerOf2MinusOne !Word8 -- 2^w -1
-  | MinusPowerOf2 !Word8 -- - 2^w
-  | MinusPowerOf2MinusOne !Word8 -- - (2^w -1)
-  | OtherInteger !Integer
-  | OtherDouble !Double
-
-guessScientificSymbolic :: Scientific -> ScientificSymbolic
-guessScientificSymbolic s = case floatingOrInteger s of
-  Left d -> OtherDouble d
-  Right i ->
-    let log2Rounded :: Word8
-        log2Rounded = round (logBase 2 (fromInteger (abs i)) :: Double)
-        guess :: Integer
-        guess = 2 ^ log2Rounded
-     in if
-          | i == 0 -> Zero
-          | guess == i -> PowerOf2 log2Rounded
-          | (guess - 1) == i -> PowerOf2MinusOne log2Rounded
-          | -guess == i -> MinusPowerOf2 log2Rounded
-          | -(guess - 1) == i -> MinusPowerOf2MinusOne log2Rounded
-          | otherwise -> OtherInteger i