diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+1.2.1
+
+- `MFunctor` and `MMonad` instances for `AccumT`
+
 1.2.0
 
 * BREAKING CHANGE: Remove instances for `ErrorT` and `ListT`
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2013, Gabriel Gonzalez
+Copyright (c) 2013, Gabriella Gonzalez
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,
@@ -9,7 +9,7 @@
 * Redistributions in binary form must reproduce the above copyright notice, this
   list of conditions and the following disclaimer in the documentation and/or
   other materials provided with the distribution.
-* Neither the name of Gabriel Gonzalez nor the names of other contributors may
+* Neither the name of Gabriella Gonzalez nor the names of other contributors may
   be used to endorse or promote products derived from this software without
   specific prior written permission.
 
diff --git a/mmorph.cabal b/mmorph.cabal
--- a/mmorph.cabal
+++ b/mmorph.cabal
@@ -1,13 +1,13 @@
 Name: mmorph
-Version: 1.2.0
+Version: 1.2.1
 Cabal-Version: >= 1.10
 Build-Type: Simple
 License: BSD3
 License-File: LICENSE
-Copyright: 2013 Gabriel Gonzalez
-Author: Gabriel Gonzalez
-Maintainer: Gabriel439@gmail.com
-Bug-Reports: https://github.com/Gabriel439/Haskell-MMorph-Library/issues
+Copyright: 2013 Gabriella Gonzalez
+Author: Gabriella Gonzalez
+Maintainer: GenuineGabriella@gmail.com
+Bug-Reports: https://github.com/Gabriella439/Haskell-MMorph-Library/issues
 Synopsis: Monad morphisms
 Description: This library provides monad morphism utilities, most commonly used
     for manipulating monad transformer stacks.
@@ -15,15 +15,15 @@
 Extra-Source-Files: CHANGELOG.md
 Source-Repository head
     Type: git
-    Location: https://github.com/Gabriel439/Haskell-MMorph-Library
+    Location: https://github.com/Gabriella439/Haskell-MMorph-Library
 
 Library
     Hs-Source-Dirs: src
     Build-Depends:
         base                >= 4.5     && < 5  ,
-        mtl                 >= 2.1     && < 2.3,
-        transformers        >= 0.2.0.0 && < 0.6,
-        transformers-compat >= 0.3     && < 0.7
+        mtl                 >= 2.1     && < 2.4,
+        transformers        >= 0.2.0.0 && < 0.7,
+        transformers-compat >= 0.3     && < 0.8
     if impl(ghc < 8.0)
         Build-Depends:
             fail == 4.9.*
diff --git a/src/Control/Monad/Morph.hs b/src/Control/Monad/Morph.hs
--- a/src/Control/Monad/Morph.hs
+++ b/src/Control/Monad/Morph.hs
@@ -78,6 +78,7 @@
     ) where
 
 import Control.Monad.Trans.Class (MonadTrans(lift))
+import qualified Control.Monad.Trans.Accum         as A
 import qualified Control.Monad.Trans.Except        as Ex
 import qualified Control.Monad.Trans.Identity      as I
 import qualified Control.Monad.Trans.Maybe         as M
@@ -115,6 +116,9 @@
     -}
     hoist :: (Monad m) => (forall a . m a -> n a) -> t m b -> t n b
 
+instance MFunctor (A.AccumT w) where
+    hoist nat m = A.AccumT (nat . A.runAccumT m)
+
 instance MFunctor (Ex.ExceptT e) where
     hoist nat m = Ex.ExceptT (nat (Ex.runExceptT m))
 
@@ -229,6 +233,11 @@
 (|>=) :: (Monad n, MMonad t) => t m b -> (forall a . m a -> t n a) -> t n b
 t |>= f = embed f t
 {-# INLINABLE (|>=) #-}
+
+instance Monoid w => MMonad (A.AccumT w) where
+    embed f m = A.AccumT $ \w -> do
+        ((b, wInner), wOuter) <- A.runAccumT (f $ A.runAccumT m w) w
+        return (b, wInner `mappend` wOuter)
 
 instance MMonad (Ex.ExceptT e) where
     embed f m = Ex.ExceptT (do