diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Revision history for language-c99-simple
 
+## 0.2.3 -- 2023-08-30
+
+* Allow building with mtl-2.3.1 (thanks RyanGlScott) (#15).
+
 ## 0.2.2 -- 2022-08-28
 
 * Added support for `sizeof` (#12).
diff --git a/language-c99-simple.cabal b/language-c99-simple.cabal
--- a/language-c99-simple.cabal
+++ b/language-c99-simple.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                language-c99-simple
-version:             0.2.2
+version:             0.2.3
 synopsis:            C-like AST to simplify writing C99 programs.
 description:
   This package is a wrapper on top of 'language-c99'. It provides a simpler
@@ -35,6 +35,6 @@
   build-depends:       base >=4.9 && <5,
                        language-c99 >= 0.2 && < 0.3,
                        language-c99-util >= 0.2 && < 0.3,
-                       mtl >= 2.2.0 && < 2.3
+                       mtl >= 2.2.0 && < 2.4
   hs-source-dirs:      src
   default-language:    Haskell2010