diff --git a/test/Test/Retrofit.hs b/test/Test/Retrofit.hs
--- a/test/Test/Retrofit.hs
+++ b/test/Test/Retrofit.hs
@@ -1,4 +1,5 @@
-{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE DeriveTraversable
+           , TemplateHaskell #-}
 
 -- | The point of this module is that it should compile _without_ importing any
 --   other Yaya modules.
@@ -6,43 +7,25 @@
 
 import           Hedgehog
 
-import qualified Yaya.Hedgehog.Expr as ExprF
 import           Yaya.Retrofit
 
 data DExpr
   = Lit Int
   | Add DExpr DExpr
   | Mult DExpr DExpr
-
-instance Projectable (->) DExpr ExprF.Expr where
-  project = \case
-    Lit i -> ExprF.Lit i
-    Add a b -> ExprF.Add a b
-    Mult a b -> ExprF.Mult a b
-
-instance Steppable (->) DExpr ExprF.Expr where
-  embed = \case
-    ExprF.Lit i -> Lit i
-    ExprF.Add a b -> Add a b
-    ExprF.Mult a b -> Mult a b
-
-instance Corecursive (->) DExpr ExprF.Expr where
-  ana ψ = embed . fmap (ana ψ) . ψ
+  deriving (Eq, Show)
 
--- | This is unsafe, but we really just want to make sure all the methods are
---   available.
-instance Recursive (->) DExpr ExprF.Expr where
-  cata φ = φ . fmap (cata φ) . project
+extractPatternFunctor defaultRules ''DExpr
 
--- | This can be derived in this case, but we want to ensure we could define it
---   if necessary.
-instance Eq DExpr where
-  (==) = recursiveEq
+-- -- | This can be derived in this case, but we want to ensure we could define it
+-- --   if necessary.
+-- instance Eq DExpr where
+--   (==) = recursiveEq
 
--- | This can be derived in this case, but we want to ensure we could define it
---   if necessary.
-instance Show DExpr where
-  showsPrec = recursiveShowsPrec
+-- -- | This can be derived in this case, but we want to ensure we could define it
+-- --   if necessary.
+-- instance Show DExpr where
+--   showsPrec = recursiveShowsPrec
 
 tests :: IO Bool
 tests = checkParallel $$(discover)
diff --git a/yaya-test.cabal b/yaya-test.cabal
--- a/yaya-test.cabal
+++ b/yaya-test.cabal
@@ -1,5 +1,5 @@
 name:                yaya-test
-version:             0.3.0.0
+version:             0.3.1.0
 synopsis:            Test suites for `yaya`.
 description:         This package should not be depended on by anything.
 homepage:            https://github.com/sellout/yaya#readme
@@ -22,7 +22,7 @@
   build-depends:       base >= 4.7 && < 5
                      , deriving-compat
                      , hedgehog
-                     , yaya >= 0.3.0
+                     , yaya >= 0.3.1
                      , yaya-hedgehog >= 0.2.0
   default-extensions:  LambdaCase
                      , MultiParamTypeClasses