diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,9 @@
+1.0.2.1
+-------
+
+- GHC-8.4.1 compatible release
+- Bump dependencies' bounds
+
 1.0.2
 -----
 
diff --git a/integer-logarithms.cabal b/integer-logarithms.cabal
--- a/integer-logarithms.cabal
+++ b/integer-logarithms.cabal
@@ -1,5 +1,5 @@
 name:               integer-logarithms
-version:            1.0.2
+version:            1.0.2.1
 cabal-version:      >= 1.10
 author:             Daniel Fischer
 copyright:          (c) 2011 Daniel Fischer
@@ -30,7 +30,8 @@
   GHC==7.8.4,
   GHC==7.10.3,
   GHC==8.0.2,
-  GHC==8.2.1
+  GHC==8.2.2,
+  GHC==8.4.1
 
 extra-source-files  : readme.md changelog.md
 
@@ -48,7 +49,7 @@
   default-language: Haskell2010
   hs-source-dirs: src
   build-depends:
-    base >= 4.3 && < 4.11,
+    base >= 4.3 && < 4.12,
     array >= 0.3 && < 0.6,
     ghc-prim < 0.6
   if impl(ghc >= 7.10)
@@ -96,12 +97,12 @@
   build-depends:
     base,
     integer-logarithms,
-    tasty >= 0.10 && < 0.12,
+    tasty >= 0.10 && < 1.1,
     tasty-smallcheck >= 0.8 && < 0.9,
-    tasty-quickcheck >= 0.8 && < 0.10,
-    tasty-hunit >= 0.9 && < 0.10,
-    QuickCheck >= 2.10 && < 2.11,
-    smallcheck >= 1.1 && < 1.2
+    tasty-quickcheck >= 0.8 && < 0.11,
+    tasty-hunit >= 0.9 && < 0.11,
+    QuickCheck >= 2.10 && < 2.12,
+    smallcheck >= 1.1.3 && < 1.2
   if !impl(ghc >= 7.10)
     build-depends: nats >= 1.1 && <1.2
 
diff --git a/test-suite/Math/NumberTheory/TestUtils.hs b/test-suite/Math/NumberTheory/TestUtils.hs
--- a/test-suite/Math/NumberTheory/TestUtils.hs
+++ b/test-suite/Math/NumberTheory/TestUtils.hs
@@ -11,7 +11,6 @@
 {-# LANGUAGE FlexibleInstances          #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiParamTypeClasses      #-}
-{-# LANGUAGE StandaloneDeriving         #-}
 
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 
@@ -22,15 +21,12 @@
   , testSmallAndQuick
   ) where
 
-import Test.SmallCheck.Series (cons2)
 import Test.Tasty
 import Test.Tasty.SmallCheck as SC
 import Test.Tasty.QuickCheck as QC hiding (Positive, NonNegative, generate, getNonNegative)
 import Test.SmallCheck.Series (Positive(..), NonNegative(..), Serial(..), Series, generate)
 
 import Control.Applicative
-import Data.Word
-import Numeric.Natural
 
 testSmallAndQuick
   :: SC.Testable IO a
@@ -40,21 +36,6 @@
   [ SC.testProperty "smallcheck" f
   , QC.testProperty "quickcheck" f
   ]
-
--------------------------------------------------------------------------------
--- Serial monadic actions
-
-instance Monad m => Serial m Word where
-  series =
-    generate (\d -> if d >= 0 then pure 0 else empty) <|> nats
-    where
-      nats = generate $ \d -> if d > 0 then [1 .. fromInteger (toInteger d)] else empty
-
-instance Monad m => Serial m Natural where
-  series =
-    generate (\d -> if d >= 0 then pure 0 else empty) <|> nats
-    where
-      nats = generate $ \d -> if d > 0 then [1 .. fromInteger (toInteger d)] else empty
 
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 -- Power