diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+## 0.1.2.0
+
+* Add `wrappedWithRunInIO`.
+
 ## 0.1.1.0
 
 * Doc improvements.
diff --git a/src/Control/Monad/IO/Unlift.hs b/src/Control/Monad/IO/Unlift.hs
--- a/src/Control/Monad/IO/Unlift.hs
+++ b/src/Control/Monad/IO/Unlift.hs
@@ -7,10 +7,10 @@
   , askRunInIO
   , withUnliftIO
   , toIO
+  , wrappedWithRunInIO
   , MonadIO (..)
   ) where
 
-import Control.Monad (liftM)
 import Control.Monad.IO.Class
 import Control.Monad.Trans.Reader (ReaderT (..))
 import Control.Monad.Trans.Identity (IdentityT (..))
@@ -57,6 +57,7 @@
   --
   -- See 'UnliftIO' for an explanation of why we need a helper
   -- datatype here.
+  --
   -- @since 0.1.0.0
   askUnliftIO :: m (UnliftIO m)
   askUnliftIO = withRunInIO (\run -> return (UnliftIO run))
@@ -99,7 +100,7 @@
     withRunInIO $ \run ->
     inner (run . runIdentityT)
 
--- | Same ask 'askUnliftIO', but returns a monomorphic function
+-- | Same as 'askUnliftIO', but returns a monomorphic function
 -- instead of a polymorphic newtype wrapper. If you only need to apply
 -- the transformation on one concrete type, this function can be more
 -- convenient.
@@ -125,3 +126,29 @@
 {-# INLINE toIO #-}
 toIO :: MonadUnliftIO m => m a -> m (IO a)
 toIO m = withRunInIO $ \run -> return $ run m
+
+{- | A helper function for implementing @MonadUnliftIO@ instances.
+Useful for the common case where you want to simply delegate to the
+underlying transformer.
+
+@since 0.1.2.0
+==== __Example__
+
+> newtype AppT m a = AppT { unAppT :: ReaderT Int (ResourceT m) a }
+>   deriving (Functor, Applicative, Monad, MonadIO)
+>   -- Unfortunately, deriving MonadUnliftIO does not work.
+>
+> instance MonadUnliftIO m => MonadUnliftIO (AppT m) where
+>   withRunInIO = wrappedWithRunInIO AppT unAppT
+-}
+{-# INLINE wrappedWithRunInIO #-}
+wrappedWithRunInIO :: MonadUnliftIO n
+                   => (n b -> m b)
+                   -- ^ The wrapper, for instance @IdentityT@.
+                   -> (forall a. m a -> n a)
+                   -- ^ The inverse, for instance @runIdentityT@.
+                   -> ((forall a. m a -> IO a) -> IO b)
+                   -- ^ The actual function to invoke 'withRunInIO' with.
+                   -> m b
+wrappedWithRunInIO wrap unwrap inner = wrap $ withRunInIO $ \run ->
+  inner $ run . unwrap
diff --git a/unliftio-core.cabal b/unliftio-core.cabal
--- a/unliftio-core.cabal
+++ b/unliftio-core.cabal
@@ -1,11 +1,13 @@
--- This file has been generated from package.yaml by hpack version 0.21.2.
+cabal-version: >= 1.10
+
+-- This file has been generated from package.yaml by hpack version 0.29.6.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 30994f07a9010e7816784501ed5ff3165c34026fa5dc555ebf1a70f6d6c0f1af
+-- hash: 9dda29b2ae88c7aba738c44b9efa373de55a416be845a7bf888fc8c108166fed
 
 name:           unliftio-core
-version:        0.1.1.0
+version:        0.1.2.0
 synopsis:       The MonadUnliftIO typeclass for unlifting monads to IO
 description:    Please see the documentation and README at <https://www.stackage.org/package/unliftio-core>
 category:       Control
@@ -16,8 +18,6 @@
 license:        MIT
 license-file:   LICENSE
 build-type:     Simple
-cabal-version:  >= 1.10
-
 extra-source-files:
     ChangeLog.md
     README.md
@@ -26,7 +26,7 @@
   hs-source-dirs:
       src
   build-depends:
-      base >=4.5 && <4.11
+      base >=4.5 && <4.12
     , transformers >=0.2 && <0.6
   exposed-modules:
       Control.Monad.IO.Unlift