diff --git a/ChasingBottoms.cabal b/ChasingBottoms.cabal
--- a/ChasingBottoms.cabal
+++ b/ChasingBottoms.cabal
@@ -1,8 +1,8 @@
 name:               ChasingBottoms
-version:            1.3.1.9
+version:            1.3.1.10
 license:            MIT
 license-file:       LICENCE
-copyright:          Copyright (c) Nils Anders Danielsson 2004-2020.
+copyright:          Copyright (c) Nils Anders Danielsson 2004-2021.
 author:             Nils Anders Danielsson
 maintainer:         http://www.cse.chalmers.se/~nad/
 synopsis:           For testing partial and infinite values.
@@ -126,8 +126,9 @@
                     GHC == 8.2.2,
                     GHC == 8.4.4,
                     GHC == 8.6.5,
-                    GHC == 8.8.3,
-                    GHC == 8.10.1
+                    GHC == 8.8.4,
+                    GHC == 8.10.2,
+                    GHC == 9.0.0.20201227
 cabal-version:      >= 1.10
 build-type:         Simple
 
@@ -152,7 +153,7 @@
 
     build-depends: QuickCheck >= 2.10 && < 2.15,
                    mtl >= 2 && < 2.3,
-                   base >= 4.2 && < 4.15,
+                   base >= 4.2 && < 4.16,
                    containers >= 0.5 && < 0.7,
                    random >= 1.0 && < 1.3,
                    syb >= 0.1.0.2 && < 0.8
@@ -185,7 +186,7 @@
 
     build-depends: QuickCheck >= 2.10 && < 2.15,
                    mtl >= 2 && < 2.3,
-                   base >= 4.2 && < 4.15,
+                   base >= 4.2 && < 4.16,
                    containers >= 0.5 && < 0.7,
                    random >= 1.0 && < 1.3,
                    syb >= 0.1.0.2 && < 0.8,
diff --git a/LICENCE b/LICENCE
--- a/LICENCE
+++ b/LICENCE
@@ -1,7 +1,7 @@
 I have chosen to distribute this library under the MIT/Expat licence:
 ---------------------------------------------------------------------
 
-Copyright (c) 2004-2020 Nils Anders Danielsson
+Copyright (c) 2004-2021 Nils Anders Danielsson
 
 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the
diff --git a/Test/ChasingBottoms.hs b/Test/ChasingBottoms.hs
--- a/Test/ChasingBottoms.hs
+++ b/Test/ChasingBottoms.hs
@@ -1,6 +1,6 @@
 -- |
 -- Module      :  Test.ChasingBottoms
--- Copyright   :  (c) Nils Anders Danielsson 2004-2020
+-- Copyright   :  (c) Nils Anders Danielsson 2004-2021
 -- License     :  See the file LICENCE.
 --
 -- Maintainer  :  http://www.cse.chalmers.se/~nad/
diff --git a/Test/ChasingBottoms/Approx.hs b/Test/ChasingBottoms/Approx.hs
--- a/Test/ChasingBottoms/Approx.hs
+++ b/Test/ChasingBottoms/Approx.hs
@@ -3,7 +3,7 @@
 
 -- |
 -- Module      :  Test.ChasingBottoms.Approx
--- Copyright   :  (c) Nils Anders Danielsson 2004-2020
+-- Copyright   :  (c) Nils Anders Danielsson 2004-2021
 -- License     :  See the file LICENCE.
 --
 -- Maintainer  :  http://www.cse.chalmers.se/~nad/
diff --git a/Test/ChasingBottoms/ApproxShow.hs b/Test/ChasingBottoms/ApproxShow.hs
--- a/Test/ChasingBottoms/ApproxShow.hs
+++ b/Test/ChasingBottoms/ApproxShow.hs
@@ -3,7 +3,7 @@
 
 -- |
 -- Module      :  Test.ChasingBottoms.ApproxShow
--- Copyright   :  (c) Nils Anders Danielsson 2004-2020
+-- Copyright   :  (c) Nils Anders Danielsson 2004-2021
 -- License     :  See the file LICENCE.
 --
 -- Maintainer  :  http://www.cse.chalmers.se/~nad/
diff --git a/Test/ChasingBottoms/ContinuousFunctions.hs b/Test/ChasingBottoms/ContinuousFunctions.hs
--- a/Test/ChasingBottoms/ContinuousFunctions.hs
+++ b/Test/ChasingBottoms/ContinuousFunctions.hs
@@ -12,7 +12,7 @@
 
 -- |
 -- Module      :  Test.ChasingBottoms.ContinuousFunctions
--- Copyright   :  (c) Nils Anders Danielsson 2005-2020
+-- Copyright   :  (c) Nils Anders Danielsson 2005-2021
 -- License     :  See the file LICENCE.
 --
 -- Maintainer  :  http://www.cse.chalmers.se/~nad/
@@ -313,7 +313,7 @@
   (_, pms') <- partition' 9 pms
   -- Use pattern matches with probability 0.33.
   (use, keep) <- partition' 2 pms'
-  let transform = compose $ fmap apply use
+  let transform = compose $ fmap (\pm -> apply pm) use
       further = concat $ fmap more use
   if Seq.null further then
     return (GenT transform, keep)
diff --git a/Test/ChasingBottoms/IsBottom.hs b/Test/ChasingBottoms/IsBottom.hs
--- a/Test/ChasingBottoms/IsBottom.hs
+++ b/Test/ChasingBottoms/IsBottom.hs
@@ -5,7 +5,7 @@
 
 -- |
 -- Module      :  Test.ChasingBottoms.IsBottom
--- Copyright   :  (c) Nils Anders Danielsson 2004-2020
+-- Copyright   :  (c) Nils Anders Danielsson 2004-2021
 -- License     :  See the file LICENCE.
 --
 -- Maintainer  :  http://www.cse.chalmers.se/~nad/
diff --git a/Test/ChasingBottoms/IsType.hs b/Test/ChasingBottoms/IsType.hs
--- a/Test/ChasingBottoms/IsType.hs
+++ b/Test/ChasingBottoms/IsType.hs
@@ -1,6 +1,6 @@
 -- |
 -- Module      :  Test.ChasingBottoms.IsType
--- Copyright   :  (c) Nils Anders Danielsson 2004-2020
+-- Copyright   :  (c) Nils Anders Danielsson 2004-2021
 -- License     :  See the file LICENCE.
 --
 -- Maintainer  :  http://www.cse.chalmers.se/~nad/
diff --git a/Test/ChasingBottoms/Nat.hs b/Test/ChasingBottoms/Nat.hs
--- a/Test/ChasingBottoms/Nat.hs
+++ b/Test/ChasingBottoms/Nat.hs
@@ -2,7 +2,7 @@
 
 -- |
 -- Module      :  Test.ChasingBottoms.Nat
--- Copyright   :  (c) Nils Anders Danielsson 2004-2020
+-- Copyright   :  (c) Nils Anders Danielsson 2004-2021
 -- License     :  See the file LICENCE.
 --
 -- Maintainer  :  http://www.cse.chalmers.se/~nad/
diff --git a/Test/ChasingBottoms/SemanticOrd.hs b/Test/ChasingBottoms/SemanticOrd.hs
--- a/Test/ChasingBottoms/SemanticOrd.hs
+++ b/Test/ChasingBottoms/SemanticOrd.hs
@@ -4,7 +4,7 @@
 
 -- |
 -- Module      :  Test.ChasingBottoms.SemanticOrd
--- Copyright   :  (c) Nils Anders Danielsson 2004-2020
+-- Copyright   :  (c) Nils Anders Danielsson 2004-2021
 -- License     :  See the file LICENCE.
 --
 -- Maintainer  :  http://www.cse.chalmers.se/~nad/
@@ -174,8 +174,7 @@
 
 -- Check children.
 childrenOK :: Rel -> Rel
-childrenOK op = and .|.. gzipWithQ (\x y -> op x y)
-  where f .|.. g = \x y -> f (g x y)
+childrenOK op x y = and (gzipWithQ (\x y -> op x y) x y)
 
 ------------------------------------------------------------------------
 
diff --git a/Test/ChasingBottoms/TimeOut.hs b/Test/ChasingBottoms/TimeOut.hs
--- a/Test/ChasingBottoms/TimeOut.hs
+++ b/Test/ChasingBottoms/TimeOut.hs
@@ -2,7 +2,7 @@
 
 -- |
 -- Module      :  Test.ChasingBottoms.TimeOut
--- Copyright   :  (c) Nils Anders Danielsson 2004-2020
+-- Copyright   :  (c) Nils Anders Danielsson 2004-2021
 -- License     :  See the file LICENCE.
 --
 -- Maintainer  :  http://www.cse.chalmers.se/~nad/