diff --git a/mmorph.cabal b/mmorph.cabal
--- a/mmorph.cabal
+++ b/mmorph.cabal
@@ -1,5 +1,5 @@
 Name: mmorph
-Version: 1.0.2
+Version: 1.0.3
 Cabal-Version: >= 1.8.0.2
 Build-Type: Simple
 License: BSD3
@@ -20,6 +20,6 @@
     Hs-Source-Dirs: src
     Build-Depends:
         base         >= 4       && < 5  ,
-        transformers >= 0.2.0.0 && < 0.4
+        transformers >= 0.2.0.0 && < 0.5
     Exposed-Modules: Control.Monad.Morph, Control.Monad.Trans.Compose
     GHC-Options: -O2