diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # ChangeLog for yesod-core
 
+## 1.6.17.3
+
+* Support for `unliftio-core` 0.2
+
 ## 1.6.17.2
 
 * Support template-haskell 2.16, build with GHC 8.10 [#1657](https://github.com/yesodweb/yesod/pull/1657)
diff --git a/src/Yesod/Core/Types.hs b/src/Yesod/Core/Types.hs
--- a/src/Yesod/Core/Types.hs
+++ b/src/Yesod/Core/Types.hs
@@ -55,7 +55,7 @@
 import Control.DeepSeq (NFData (rnf))
 import Yesod.Core.TypeCache (TypeMap, KeyedTypeMap)
 import Control.Monad.Logger (MonadLoggerIO (..))
-import UnliftIO (MonadUnliftIO (..), UnliftIO (..))
+import UnliftIO (MonadUnliftIO (..))
 
 -- Sessions
 type SessionMap = Map Text ByteString
@@ -437,9 +437,8 @@
     primitive = liftIO . primitive
 -- | @since 1.4.38
 instance MonadUnliftIO (WidgetFor site) where
-  {-# INLINE askUnliftIO #-}
-  askUnliftIO = WidgetFor $ \wd ->
-                return (UnliftIO (flip unWidgetFor wd))
+  {-# INLINE withRunInIO #-}
+  withRunInIO inner = WidgetFor $ \x -> inner $ flip unWidgetFor x
 instance MonadReader (WidgetData site) (WidgetFor site) where
     ask = WidgetFor return
     local f (WidgetFor g) = WidgetFor $ g . f
@@ -476,9 +475,8 @@
 
 -- | @since 1.4.38
 instance MonadUnliftIO (HandlerFor site) where
-  {-# INLINE askUnliftIO #-}
-  askUnliftIO = HandlerFor $ \r ->
-                return (UnliftIO (flip unHandlerFor r))
+  {-# INLINE withRunInIO #-}
+  withRunInIO inner = HandlerFor $ \x -> inner $ flip unHandlerFor x
 
 instance MonadThrow (HandlerFor site) where
     throwM = liftIO . throwM
@@ -549,9 +547,8 @@
 
 -- | @since 1.4.38
 instance MonadUnliftIO (SubHandlerFor child master) where
-  {-# INLINE askUnliftIO #-}
-  askUnliftIO = SubHandlerFor $ \r ->
-                return (UnliftIO (flip unSubHandlerFor r))
+  {-# INLINE withRunInIO #-}
+  withRunInIO inner = SubHandlerFor $ \x -> inner $ flip unSubHandlerFor x
 
 instance MonadThrow (SubHandlerFor child master) where
     throwM = liftIO . throwM
diff --git a/yesod-core.cabal b/yesod-core.cabal
--- a/yesod-core.cabal
+++ b/yesod-core.cabal
@@ -1,5 +1,5 @@
 name:            yesod-core
-version:         1.6.17.2
+version:         1.6.17.3
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>