diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,15 @@
+* 3000.11.5 (17 March 2023)
+
+  - Updates for `mtl-2.3`.
+  - Add an upper bound on `mtl` to prevent future breakage.
+
 * 3000.11.4.1 (9 July 2020)
 
   - Support GHC-8.10
+
+  - r1 (29 Sep 2021): support GHC 9.0
+  - r2 (21 March 2022): support GHC 9.2
+  - r3 (9 Sep 2022): support GHC 9.4
 
 * 3000.11.4 (24 January 2020)
 
diff --git a/Network/XmlRpc/Internals.hs b/Network/XmlRpc/Internals.hs
--- a/Network/XmlRpc/Internals.hs
+++ b/Network/XmlRpc/Internals.hs
@@ -48,9 +48,11 @@
 
 import           Control.Exception
 import           Control.Monad
-import           Control.Monad.Except
+import           Control.Monad.Except (ExceptT, MonadError(..), runExceptT)
 import qualified Control.Monad.Fail as Fail
 import           Control.Monad.Fail (MonadFail)
+import           Control.Monad.IO.Class
+import           Control.Monad.Trans
 import           Data.Char
 import           Data.List
 import           Data.Maybe
diff --git a/Network/XmlRpc/Server.hs b/Network/XmlRpc/Server.hs
--- a/Network/XmlRpc/Server.hs
+++ b/Network/XmlRpc/Server.hs
@@ -32,7 +32,7 @@
 
 import qualified Codec.Binary.UTF8.String   as U
 import           Control.Exception
-import           Control.Monad.Except
+import           Control.Monad.Trans
 import           Data.ByteString.Lazy.Char8 (ByteString)
 import qualified Data.ByteString.Lazy.Char8 as B
 import           System.IO
diff --git a/haxr.cabal b/haxr.cabal
--- a/haxr.cabal
+++ b/haxr.cabal
@@ -1,5 +1,5 @@
 Name: haxr
-Version: 3000.11.4.1
+Version: 3000.11.5
 Cabal-version: >=1.10
 Build-type: Simple
 Copyright: Bjorn Bringert, 2003-2006
@@ -22,7 +22,7 @@
         examples/test_client.hs       examples/test_server.hs       examples/time-xmlrpc-com.hs
         examples/validate.hs          examples/Makefile
 Bug-reports: https://github.com/byorgey/haxr/issues
-Tested-with: GHC ==8.0.2 || ==8.2.2 || ==8.4.4 || ==8.6.5 || ==8.8.3 || ==8.10.1
+Tested-with: GHC ==8.4.4 || ==8.6.5 || ==8.8.4 || ==8.10.7 || ==9.0.2 || ==9.2.4 || ==9.4.1
 
 Source-repository head
   type:     git
@@ -33,9 +33,9 @@
    default: True
 
 Library
-  Build-depends: base >= 4.9 && < 4.15,
-                 base-compat >= 0.8 && < 0.12,
-                 mtl,
+  Build-depends: base >= 4.9 && < 4.18,
+                 base-compat >= 0.8 && < 0.13,
+                 mtl < 2.4,
                  mtl-compat,
                  network < 3.2,
                  http-streams,