diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -25,7 +25,7 @@
 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGE.
 
-Copyright (c) 2011-2021, Geoffrey Mainland
+Copyright (c) 2011-2023, Geoffrey Mainland
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,
diff --git a/exception-transformers.cabal b/exception-transformers.cabal
--- a/exception-transformers.cabal
+++ b/exception-transformers.cabal
@@ -1,10 +1,10 @@
 name:           exception-transformers
-version:        0.4.0.11
+version:        0.4.0.12
 cabal-version:  >= 1.10
 license:        BSD3
 license-file:   LICENSE
 copyright:      (c) 2009-2010 Harvard University
-                (c) 2011-2021 Geoffrey Mainland
+                (c) 2011-2023 Geoffrey Mainland
 author:         Geoffrey Mainland <mainland@drexel.edu>
 maintainer:     Geoffrey Mainland <mainland@drexel.edu>
 stability:      alpha
@@ -17,7 +17,7 @@
                 the transformers package.
 tested-with:    GHC==7.4.2, GHC==7.6.3, GHC==7.8.4, GHC==7.10.3, GHC==8.0.2,
                 GHC==8.2.2, GHC==8.4.3, GHC==8.6.5, GHC==8.8.4, GHC==8.10.7,
-                GHC==9.0.1, GHC==9.2.1
+                GHC==9.0.2, GHC==9.2.8, GHC==9.4.5, GHC==9.6.2
 
 build-type:     Simple
 
@@ -48,7 +48,7 @@
     exception-transformers,
     test-framework         >= 0.8 && < 0.9,
     test-framework-hunit   >= 0.3 && < 0.4,
-    transformers           >= 0.2 && < 0.6,
+    transformers           >= 0.2 && < 0.7,
     transformers-compat    >= 0.3 && < 0.8
 
   ghc-options:
diff --git a/tests/unit/Main.hs b/tests/unit/Main.hs
--- a/tests/unit/Main.hs
+++ b/tests/unit/Main.hs
@@ -15,7 +15,9 @@
 #endif
 
 import Control.Monad.Exception
+#if !MIN_VERSION_transformers(0,6,0)
 import Control.Monad.Trans.Error
+#endif /* !MIN_VERSION_transformers(0,6,0) */
 import Control.Monad.Trans.Except
 import Control.Monad.IO.Class
 import Data.IORef
@@ -27,10 +29,13 @@
 main = defaultMain tests
 
 tests :: [Test]
-tests = [ errorTests
-        , exceptTests
+tests = [ exceptTests
+#if !MIN_VERSION_transformers(0,6,0)
+        , errorTests
+#endif /* !MIN_VERSION_transformers(0,6,0) */
         ]
 
+#if !MIN_VERSION_transformers(0,6,0)
 errorTests :: Test
 errorTests = testGroup "ErrorT tests"
     [testCase (conl ++ " " ++ whatl) (mkErrorTest con what) | (conl, con) <- cons, (whatl, what) <- whats]
@@ -56,6 +61,7 @@
       where
         expected :: String
         expected = "sequel called"
+#endif /* !MIN_VERSION_transformers(0,6,0) */
 
 exceptTests :: Test
 exceptTests = testGroup "ExceptT tests"