diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,8 @@
 # Changelog for free-category
 
+## Version 0.0.4.2
+- updated for *GHC 8.10.1*
+
 ## Version 0.0.4.0
 - hoistOp
 - Renamed `Control.Category.FreeEff` module as `Control.Category.FreeEffect`
diff --git a/free-category.cabal b/free-category.cabal
--- a/free-category.cabal
+++ b/free-category.cabal
@@ -1,11 +1,12 @@
+cabal-version:  2.0
 name:           free-category
-version:        0.0.4.1
+version:        0.0.4.2
 synopsis:       efficient data types for free categories and arrows
 description:
-  Provide various data types for free categories / type aligned queues, type
-  classes which allow to write abstract categories with side effects (Kleisli
-  like categories).  These are useful for encoding type safe state machines.
-  Free arrows are also provided.
+  This package provides various data types for free categories, type
+  aligned queues, arrows and type classes which allow to write abstract
+  categories with side effects (Kleisli like categories).  These are useful
+  for encoding type safe state machines.  Free arrows are also provided.
 category:       Algebra, Control, Monads, Category
 homepage:       https://github.com/coot/free-category#readme
 bug-reports:    https://github.com/coot/free-category/issues
@@ -15,7 +16,6 @@
 license:        MPL-2.0
 license-file:   LICENSE
 build-type:     Simple
-cabal-version:  >= 1.10
 extra-source-files:
     ChangeLog.md
     README.md
@@ -23,7 +23,7 @@
     bench/report-O1.md
     bench/report-O2.md
 stability:      experimental
-tested-with:    GHC==8.0.2, GHC==8.2.2, GHC==8.4.4, GHC==8.6.5, GHC==8.8.1
+tested-with:    GHC==8.6.5, GHC==8.8.3, GHC==8.10.1
 
 source-repository head
   type: git
@@ -37,11 +37,13 @@
       Control.Category.FreeEffect
   other-modules:
       Paths_free_category
+  autogen-modules:
+      Paths_free_category
   hs-source-dirs:
       src
   build-depends:
       base          >= 4.9 && <5
-    , free-algebras >= 0.0.8.0
+    , free-algebras >= 0.0.8.2
   ghc-options:
     -Wall
     -fwarn-incomplete-record-updates
diff --git a/src/Control/Category/Free.hs b/src/Control/Category/Free.hs
--- a/src/Control/Category/Free.hs
+++ b/src/Control/Category/Free.hs
@@ -127,20 +127,20 @@
 fromC = hoistFreeH2
 {-# INLINE fromC #-}
 
-liftC :: forall (f :: k -> k -> *) a b.
+liftC :: forall k (f :: k -> k -> *) a b.
          f a b
       -> C f a b
 liftC = \f -> C $ \k -> k f
 {-# INLINE [1] liftC #-}
 
-consC :: forall (f :: k -> k -> *) a b c.
+consC :: forall k (f :: k -> k -> *) a b c.
          f b c
       -> C f a b
       -> C f a c
 consC bc ab = liftC bc `composeC` ab
 {-# INLINE [1] consC #-}
 
-foldNatC :: forall (f :: k -> k -> *) c a b.
+foldNatC :: forall k (f :: k -> k -> *) c a b.
             Category c
          => (forall x y. f x y -> c x y)
          -> C f a b
diff --git a/src/Control/Category/Free/Internal.hs b/src/Control/Category/Free/Internal.hs
--- a/src/Control/Category/Free/Internal.hs
+++ b/src/Control/Category/Free/Internal.hs
@@ -75,7 +75,8 @@
 
 -- | 'Op' is an endo-functor of the category of categories.
 --
-hoistOp :: forall (f :: k -> k -> *)
+hoistOp :: forall k
+                  (f :: k -> k -> *)
                   (g :: k -> k -> *)
                   a b.
            (forall x y. f x y -> g x y)
@@ -129,7 +130,7 @@
 lengthListTr NilTr = 0
 lengthListTr (ConsTr _ xs) = 1 + lengthListTr xs
 
-composeL :: forall (f :: k -> k -> *) x y z.
+composeL :: forall k (f :: k -> k -> *) x y z.
             ListTr f y z
          -> ListTr f x y
          -> ListTr f x z
@@ -137,12 +138,12 @@
 composeL NilTr         ys = ys
 {-# INLINE [1] composeL #-}
 
-liftL :: forall (f :: k -> k -> *) x y.
+liftL :: forall k (f :: k -> k -> *) x y.
          f x y -> ListTr f x y
 liftL f = ConsTr f NilTr
 {-# INLINE [1] liftL #-}
 
-foldNatL :: forall (f :: k -> k -> *) c a b.
+foldNatL :: forall k (f :: k -> k -> *) c a b.
             Category c
          => (forall x y. f x y -> c x y)
          -> ListTr f a b
@@ -172,7 +173,7 @@
 
 -- | 'foldr' of a 'ListTr'
 --
-foldrL :: forall (f :: k -> k -> *) c a b d.
+foldrL :: forall k (f :: k -> k -> *) c a b d.
           (forall x y z. f y z -> c x y -> c x z)
        -> c a b
        -> ListTr f b d
@@ -185,7 +186,7 @@
 --
 -- TODO: make it strict, like 'foldl''.
 --
-foldlL :: forall (f :: k -> k -> *) c a b d.
+foldlL :: forall k (f :: k -> k -> *) c a b d.
           (forall x y z. c y z -> f x y -> c x z)
        -> c b d
        -> ListTr f a b
@@ -294,7 +295,7 @@
 {-# complete NilQ, ConsQ #-}
 #endif
 
-composeQ :: forall (f :: k -> k -> *) x y z.
+composeQ :: forall k (f :: k -> k -> *) x y z.
             Queue f y z
          -> Queue f x y
          -> Queue f x z
@@ -306,7 +307,7 @@
 nilQ = Queue NilTr NilTr NilTr
 {-# INLINE [1] nilQ #-}
 
-consQ :: forall (f :: k -> k -> *) a b c.
+consQ :: forall k (f :: k -> k -> *) a b c.
          f b c
       -> Queue f a b
       -> Queue f a c
@@ -326,7 +327,7 @@
 unconsQ _                         = error "Queue.uncons: invariant violation"
 {-# INLINE unconsQ #-}
 
-snocQ :: forall (f :: k -> k -> *) a b c.
+snocQ :: forall k (f :: k -> k -> *) a b c.
          Queue f b c
       -> f a b
       -> Queue f a c
@@ -335,7 +336,7 @@
 
 -- | 'foldr' of a 'Queue'
 --
-foldrQ :: forall (f :: k -> k -> *) c a b d.
+foldrQ :: forall k (f :: k -> k -> *) c a b d.
           (forall x y z. f y z -> c x y -> c x z)
        -> c a b
        -> Queue f b d
@@ -367,7 +368,7 @@
 
 #-}
 
-liftQ :: forall (f :: k -> k -> *) a b.
+liftQ :: forall k (f :: k -> k -> *) a b.
          f a b -> Queue f a b
 liftQ = \fab -> ConsQ fab NilQ
 {-# INLINE [1] liftQ #-}
@@ -376,7 +377,7 @@
 --
 -- /complexity/ @O\(n\)@
 --
-foldNatQ :: forall (f :: k -> k -> *) c a b.
+foldNatQ :: forall k (f :: k -> k -> *) c a b.
             Category c
          => (forall x y. f x y -> c x y)
          -> Queue f a b
@@ -407,7 +408,7 @@
 --
 -- TODO: make it strict, like 'foldl''.
 --
-foldlQ :: forall (f :: k -> k -> *) c a b d.
+foldlQ :: forall k (f :: k -> k -> *) c a b d.
           (forall x y z. c y z -> f x y -> c x z)
        -> c b d
        -> Queue f a b
@@ -433,7 +434,8 @@
 -- categories), thus one can hoist the transitions using a natural
 -- transformation.  This in analogy to @'map' :: (a -> b) -> [a] -> [b]@.
 --
-hoistQ :: forall (f :: k -> k -> *)
+hoistQ :: forall k
+                 (f :: k -> k -> *)
                  (g :: k -> k -> *)
                  a  b.
           (forall x y. f x y -> g x y)