diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,6 @@
+## 0.1.6 [2021.04.30]
+* Make the test suite compile on recent GHCs.
+
 ## 0.1.5 [2021.02.17]
 * The build-type has been changed from `Custom` to `Simple`.
   To achieve this, the `doctests` test suite has been removed in favor of using
diff --git a/structs.cabal b/structs.cabal
--- a/structs.cabal
+++ b/structs.cabal
@@ -1,6 +1,6 @@
 name:          structs
 category:      Data
-version:       0.1.5
+version:       0.1.6
 license:       BSD3
 cabal-version: 1.22
 license-file:  LICENSE
@@ -15,8 +15,9 @@
              , 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 == 8.10.4
+             , GHC == 9.0.1
 synopsis:      Strict GC'd imperative object-oriented programming with cheap pointers.
 description:
   This project is an experiment with a small GC'd strict mutable imperative universe with cheap pointers inside of the GHC runtime system.
@@ -34,7 +35,7 @@
   build-depends:
     base >= 4.9 && < 5,
     deepseq,
-    template-haskell >= 2.11 && < 2.18,
+    template-haskell >= 2.11 && < 2.19,
     th-abstraction >= 0.4 && < 0.5,
     ghc-prim,
     primitive
diff --git a/tests/unit.hs b/tests/unit.hs
--- a/tests/unit.hs
+++ b/tests/unit.hs
@@ -7,7 +7,6 @@
 import Test.QuickCheck.Modifiers (NonEmptyList (..))
 import Test.Tasty.HUnit
 
-import Data.List
 import Data.Ord
 
 import Control.Exception