diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,12 @@
 
 ### Non-breaking changes
 
+## 1.3.1.0
+
+### Non-breaking changes
+
+* Added `forkFinally` to `MonadFork`.
+
 ## 1.3.0.0
 
 - `io-sim-1.3.0.0`.
diff --git a/io-classes.cabal b/io-classes.cabal
--- a/io-classes.cabal
+++ b/io-classes.cabal
@@ -1,6 +1,6 @@
 cabal-version:       3.0
 name:                io-classes
-version:             1.3.0.0
+version:             1.3.1.0
 synopsis:            Type classes for concurrency with STM, ST and timing
 description:
   IO Monad class hierarchy compatible with
diff --git a/src/Control/Monad/Class/MonadFork.hs b/src/Control/Monad/Class/MonadFork.hs
--- a/src/Control/Monad/Class/MonadFork.hs
+++ b/src/Control/Monad/Class/MonadFork.hs
@@ -10,7 +10,7 @@
   ) where
 
 import qualified Control.Concurrent as IO
-import           Control.Exception (AsyncException (ThreadKilled), Exception)
+import           Control.Exception (AsyncException (ThreadKilled), Exception, SomeException)
 import           Control.Monad.Reader (ReaderT (..), lift)
 import           Data.Kind (Type)
 import qualified GHC.Conc.Sync as IO (labelThread)
@@ -35,6 +35,7 @@
   forkIO           :: m () -> m (ThreadId m)
   forkOn           :: Int -> m () -> m (ThreadId m)
   forkIOWithUnmask :: ((forall a. m a -> m a) -> m ()) -> m (ThreadId m)
+  forkFinally      :: m a -> (Either SomeException a -> m ()) -> m (ThreadId m)
   throwTo          :: Exception e => ThreadId m -> e -> m ()
 
   killThread       :: ThreadId m -> m ()
@@ -52,6 +53,7 @@
   forkIO           = IO.forkIO
   forkOn           = IO.forkOn
   forkIOWithUnmask = IO.forkIOWithUnmask
+  forkFinally      = IO.forkFinally
   throwTo          = IO.throwTo
   killThread       = IO.killThread
   yield            = IO.yield
@@ -68,5 +70,7 @@
                          let restore' :: ReaderT e m a -> ReaderT e m a
                              restore' (ReaderT f) = ReaderT $ restore . f
                          in runReaderT (k restore') e
+  forkFinally f k     = ReaderT $ \e -> forkFinally (runReaderT f e)
+                                      $ \err -> runReaderT (k err) e
   throwTo e t = lift (throwTo e t)
   yield       = lift yield