diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,8 @@
+0.6.5
+---
+* Allowed mtl 2.2
+* Removed unused `transformers` dependency
+
 0.6.4
 ---
 * Allow exceptions 0.6
diff --git a/tagged-transformer.cabal b/tagged-transformer.cabal
--- a/tagged-transformer.cabal
+++ b/tagged-transformer.cabal
@@ -1,5 +1,5 @@
 name:           tagged-transformer
-version:        0.6.4
+version:        0.6.5
 license:        BSD3
 license-file:   LICENSE
 author:         Edward A. Kmett
@@ -31,11 +31,10 @@
     contravariant             >= 0.3      && < 1,
     distributive              >= 0.3      && < 1,
     exceptions                >= 0.6      && < 1,
-    mtl                       >= 2.0.1    && < 2.2,
+    mtl                       >= 2.0.1    && < 2.3,
     reflection                >= 1.1.6    && < 2,
     semigroupoids             >= 4        && < 5,
-    tagged                    >= 0.4.4    && < 1,
-    transformers              >= 0.2      && < 0.4
+    tagged                    >= 0.4.4    && < 1
 
   exposed-modules:
     Data.Functor.Trans.Tagged