diff --git a/.hlint.yaml b/.hlint.yaml
--- a/.hlint.yaml
+++ b/.hlint.yaml
@@ -1,4 +1,4 @@
-- arguments: [--cpp-define=HLINT, --cpp-ansi]
+- arguments: [-XCPP, --cpp-define=HLINT, --cpp-ansi]
 
 - ignore: {name: Reduce duplication}
 - ignore: {name: Redundant lambda}
diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,7 @@
+0.7.8 [2022.05.18]
+------------------
+* Allow building with `mtl-2.3.*` and `transformers-0.6.*`.
+
 0.7.7 [2021.11.16]
 ------------------
 * Drop support for pre-8.0 versions of GHC.
diff --git a/folds.cabal b/folds.cabal
--- a/folds.cabal
+++ b/folds.cabal
@@ -1,6 +1,6 @@
 name:          folds
 category:      Data, Comonads, Enumerator
-version:       0.7.7
+version:       0.7.8
 license:       BSD3
 cabal-version: >= 1.10
 license-file:  LICENSE
@@ -18,8 +18,8 @@
              , 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 == 9.2.2
 
 extra-source-files:
   .gitignore
@@ -56,12 +56,12 @@
     data-reify        >= 0.6   && < 0.7,
     distributive      >= 0.3   && < 1,
     lens              >= 4     && < 6,
-    mtl               >= 2.0.1 && < 2.3,
+    mtl               >= 2.0.1 && < 2.4,
     pointed           >= 4     && < 6,
     profunctors       >= 5     && < 6,
     reflection        >= 1.3   && < 3,
     semigroupoids     >= 4     && < 6,
-    transformers      >= 0.3   && < 0.6,
+    transformers      >= 0.3   && < 0.7,
     unordered-containers >= 0.2 && < 0.3,
     vector            >= 0.10  && < 0.13
 
diff --git a/src/Data/Fold/Internal.hs b/src/Data/Fold/Internal.hs
--- a/src/Data/Fold/Internal.hs
+++ b/src/Data/Fold/Internal.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE PatternGuards #-}
 {-# LANGUAGE DeriveFoldable #-}