diff --git a/hierarchy.cabal b/hierarchy.cabal
--- a/hierarchy.cabal
+++ b/hierarchy.cabal
@@ -1,12 +1,12 @@
 name:          hierarchy
-version:       0.3.1.3
+version:       0.3.1.4
 synopsis:      Pipes-based library for predicated traversal of generated trees
 description:   Pipes-based library for predicated traversal of generated trees.
 homepage:      https://github.com/jwiegley/hierarchy
 license:       BSD3
 license-file:  LICENSE
 author:        John Wiegley
-maintainer:    johnw@newartisans.com
+maintainer:    damian.nadales@gmail.com
 copyright:     Copyright 2015 (c) John Wiegley. All Rights Reserved.
 category:      Data
 build-type:    Simple
@@ -23,17 +23,17 @@
       Control.Cond
     , Pipes.Tree
   build-depends:       
-      base                >=4.7  && <4.11
-    , transformers        >=0.3  && <0.6
-    , transformers-base   >=0.3  && <0.6
-    , transformers-compat >=0.3  && <0.6
+      base                >=4.7  && <4.12
+    , transformers        >=0.3  && <0.7
+    , transformers-base   >=0.3  && <0.7
+    , transformers-compat >=0.3  && <0.7
     , exceptions          >=0.8  && <0.9
     , mmorph              >=1.0  && <1.3
-    , mtl                 >=2.1  && <2.3
+    , mtl                 >=2.1  && <2.4
     , monad-control       >=1.0  && <1.1
     , semigroups          >=0.16 && <0.19
-    , free                >=4.10 && <4.13
-    , pipes               >=4.1  && <4.5
+    , free                >=4.10 && < 6
+    , pipes               >=4.1  && < 4.5
   default-language:    Haskell2010
 
 Test-suite doctests
@@ -58,7 +58,7 @@
       base >=3
     , hierarchy
     , pipes              >=4.1  && <4.5
-    , transformers       >=0.3  && <0.6
-    , mtl                >=2.1  && <2.3
+    , transformers       >=0.3  && <0.7
+    , mtl                >=2.1  && <2.4
     , hspec              >=1.4.4
     , hspec-expectations >=0.3