diff --git a/kan-extensions.cabal b/kan-extensions.cabal
--- a/kan-extensions.cabal
+++ b/kan-extensions.cabal
@@ -1,6 +1,6 @@
 name:          kan-extensions
 category:      Data Structures, Monads, Comonads, Functors
-version:       4.1
+version:       4.1.0.1
 license:       BSD3
 cabal-version: >= 1.6
 license-file:  LICENSE
@@ -51,6 +51,7 @@
     mtl           >= 2.0.1   && < 2.3,
     pointed       >= 4       && < 5,
     semigroupoids >= 4       && < 5,
+    tagged        >= 0.7.2   && < 1,
     transformers  >= 0.2     && < 0.5
 
   exposed-modules: