--- a/reducers.cabal
+++ b/reducers.cabal
@@ -25,7 +25,7 @@ library
   build-depends:
     base                   >= 4        && < 5,
     array                  >= 0.3      && < 0.6,
-    transformers           >= 0.2      && < 0.5,
+    transformers           >= 0.2      && < 0.6,
     bytestring             >= 0.9.1    && < 0.11,
     containers             >= 0.3      && < 0.6,
     fingertree             >= 0.1      && < 0.2,