diff --git a/success.cabal b/success.cabal
--- a/success.cabal
+++ b/success.cabal
@@ -1,7 +1,7 @@
 name:
   success
 version:
-  0.2.5.1
+  0.2.6
 synopsis:
   A version of Either specialised for encoding of success or failure
 description:
@@ -52,6 +52,6 @@
     transformers-base >= 0.4 && < 0.5,
     monad-control >= 1 && < 2,
     mtl >= 2 && < 3,
-    transformers >= 0.3 && < 0.6,
+    transformers >= 0.4 && < 0.6,
     base >= 4.7 && < 5