diff --git a/CHANGELOG.rst b/CHANGELOG.rst
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -7,6 +7,19 @@
 .. _PVP: https://pvp.haskell.org/
 
 
+1.11.0.3 (2023-06-17)
+---------------------
+
+* Git: :tag:`concurrency-1.11.0.3`
+* Hackage: :hackage:`concurrency-1.11.0.3`
+
+Miscellaneous
+~~~~~~~~~~~~~
+
+* The upper bound on :hackage:`mtl` is <2.4.
+* The upper bound on :hackage:`transformers` is <0.7.
+
+
 1.11.0.2 (2021-08-15)
 ---------------------
 
diff --git a/Control/Concurrent/Classy/Async.hs b/Control/Concurrent/Classy/Async.hs
--- a/Control/Concurrent/Classy/Async.hs
+++ b/Control/Concurrent/Classy/Async.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE RankNTypes #-}
 
 -- |
@@ -174,7 +175,11 @@
 -- | @since 1.1.2.0
 instance (MonadConc m, Monoid a) => Monoid (Concurrently m a) where
   mempty = pure mempty
+#if MIN_VERSION_base(4,11,0)
+  mappend = (<>)
+#else
   mappend = liftA2 mappend
+#endif
 
 -------------------------------------------------------------------------------
 -- Spawning
@@ -754,7 +759,7 @@
 --
 -- @since 1.1.2.0
 replicateConcurrently :: MonadConc m => Int -> m a -> m [a]
-replicateConcurrently i = runConcurrently . sequenceA . replicate i . Concurrently
+replicateConcurrently i = runConcurrently . replicateM i . Concurrently
 
 -- | 'replicateConcurrently_' is 'replicateConcurrently' with the
 -- return values discarded.
diff --git a/concurrency.cabal b/concurrency.cabal
--- a/concurrency.cabal
+++ b/concurrency.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                concurrency
-version:             1.11.0.2
+version:             1.11.0.3
 synopsis:            Typeclasses, functions, and data types for concurrency and STM.
 
 description:
@@ -32,7 +32,7 @@
 source-repository this
   type:     git
   location: https://github.com/barrucadu/dejafu.git
-  tag:      concurrency-1.11.0.2
+  tag:      concurrency-1.11.0.3
 
 library
   exposed-modules:     Control.Monad.Conc.Class
@@ -65,9 +65,9 @@
                      , atomic-primops    >=0.8  && <0.9
                      , exceptions        >=0.7  && <0.11
                      , monad-control     >=1.0  && <1.1
-                     , mtl               >=2.2  && <2.3
+                     , mtl               >=2.2  && <2.4
                      , stm               >=2.4  && <2.6
-                     , transformers      >=0.5  && <0.6
+                     , transformers      >=0.5  && <0.7
   -- hs-source-dirs:      
   default-language:    Haskell2010
   ghc-options:         -Wall