diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to the [Haskell Package Versioning Policy](https://pvp.haskell.org/).
 
+## 0.2.1.0 – 2019–01–08
+### Added
+- exports of type class methods via `Yaya.Retrofit`
+
 ## 0.2.0.0 – 2019–01–08
 ### Added
 - `DFunctor` instances for `Mu` and `Nu`
diff --git a/src/Yaya/Retrofit.hs b/src/Yaya/Retrofit.hs
--- a/src/Yaya/Retrofit.hs
+++ b/src/Yaya/Retrofit.hs
@@ -5,10 +5,10 @@
   ) where
 
 import Yaya.Fold
-       ( Corecursive
-       , Projectable
-       , Recursive
+       ( Corecursive (..)
+       , Projectable (..)
+       , Recursive (..)
        , recursiveEq
        , recursiveShowsPrec
-       , Steppable
+       , Steppable (..)
        )
diff --git a/test/Test/Fold/Retrofit.hs b/test/Test/Fold/Retrofit.hs
new file mode 100644
--- /dev/null
+++ b/test/Test/Fold/Retrofit.hs
@@ -0,0 +1,28 @@
+{-# LANGUAGE TemplateHaskell  #-}
+{-# LANGUAGE TypeApplications #-}
+
+module Test.Fold.Retrofit where
+
+import           Hedgehog
+import qualified Hedgehog.Gen as Gen
+
+import           Yaya.Fold.Common
+import           Yaya.Hedgehog.Expr
+import           Yaya.Hedgehog.Fold
+
+import           Test.Retrofit
+
+prop_exprAnaRefl :: Property
+prop_exprAnaRefl =
+  property $ law_anaRefl =<< forAll (Gen.sized (expression @DExpr))
+
+prop_exprCataCancel :: Property
+prop_exprCataCancel =
+  property $ law_cataCancel size =<< forAll (genExpr (Gen.sized (expression @DExpr)))
+
+prop_exprCataRefl :: Property
+prop_exprCataRefl =
+  property $ law_cataRefl =<< forAll (Gen.sized (expression @DExpr))
+
+tests :: IO Bool
+tests = checkParallel $$(discover)
diff --git a/test/Test/Retrofit.hs b/test/Test/Retrofit.hs
new file mode 100644
--- /dev/null
+++ b/test/Test/Retrofit.hs
@@ -0,0 +1,41 @@
+-- | The point of this module is that it should compile _without_ importing any
+--   other Yaya modules.
+module Test.Retrofit where
+
+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
+
+-- | 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
+
+-- | 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
diff --git a/test/test.hs b/test/test.hs
--- a/test/test.hs
+++ b/test/test.hs
@@ -4,6 +4,7 @@
 
 import qualified Test.Fold as Fold
 import qualified Test.Fold.Common as Fold.Common
+import qualified Test.Fold.Retrofit as Fold.Retrofit
 
 main :: IO ()
 main = do
@@ -12,6 +13,7 @@
 
   results <- sequence [ Fold.tests
                       , Fold.Common.tests
+                      , Fold.Retrofit.tests
                       ]
 
   unless (and results) exitFailure
diff --git a/yaya.cabal b/yaya.cabal
--- a/yaya.cabal
+++ b/yaya.cabal
@@ -1,5 +1,5 @@
 name:                yaya
-version:             0.2.0.0
+version:             0.2.1.0
 synopsis:            Total recursion schemes.
 description:         Recursion schemes allow you to separate recursion from your
                      business logic – making your own operations simpler, more
@@ -63,11 +63,15 @@
   main-is:             test.hs
   other-modules:       Test.Fold
                      , Test.Fold.Common
+                     , Test.Fold.Retrofit
+                     , Test.Retrofit
   build-depends:       base
                      , deriving-compat
                      , hedgehog
                      , yaya >= 0.1.0
                      , yaya-hedgehog >= 0.1.0
+  default-extensions:  LambdaCase
+                     , MultiParamTypeClasses
   ghc-options:         -threaded -rtsopts -with-rtsopts=-N -Wall
   default-language:    Haskell2010