diff --git a/app/App/Codec.hs b/app/App/Codec.hs
--- a/app/App/Codec.hs
+++ b/app/App/Codec.hs
@@ -13,6 +13,4 @@
         go lbs = case LBS.splitAt 4 lbs of
           (lt, rt) -> if LBS.length lt == 4
             then lt:go rt
-            else if LBS.length lt == 0
-              then []
-              else [LBS.take 4 (lt <> LBS.replicate 4 0)]
+            else [LBS.take 4 (lt <> LBS.replicate 4 0) | LBS.length lt /= 0]
diff --git a/app/App/Commands.hs b/app/App/Commands.hs
--- a/app/App/Commands.hs
+++ b/app/App/Commands.hs
@@ -4,6 +4,8 @@
 import App.Commands.LoadSave
 import Options.Applicative
 
+{- HLINT ignore "Monoid law, left identity"  -}
+
 commands :: Parser (IO ())
 commands = commandsGeneral
 
diff --git a/app/App/Commands/CreateIndex.hs b/app/App/Commands/CreateIndex.hs
--- a/app/App/Commands/CreateIndex.hs
+++ b/app/App/Commands/CreateIndex.hs
@@ -26,8 +26,9 @@
 import qualified System.IO                            as IO
 import qualified System.IO.Temp                       as RIO
 
-{-# ANN module ("HLint: ignore Reduce duplication"  :: String) #-}
-{-# ANN module ("HLint: ignore Redundant do"        :: String) #-}
+{- HLINT ignore "Monoid law, left identity"  -}
+{- HLINT ignore "Reduce duplication"  -}
+{- HLINT ignore "Redundant do"        -}
 
 readWord32s :: MonadIO m => FilePath -> m [Word32]
 readWord32s fp = do
diff --git a/app/App/Commands/LoadSave.hs b/app/App/Commands/LoadSave.hs
--- a/app/App/Commands/LoadSave.hs
+++ b/app/App/Commands/LoadSave.hs
@@ -20,8 +20,8 @@
 import qualified HaskellWorks.Data.PackedVector.PackedVector64 as PV
 import qualified System.IO                                     as IO
 
-{-# ANN module ("HLint: ignore Reduce duplication"  :: String) #-}
-{-# ANN module ("HLint: ignore Redundant do"        :: String) #-}
+{- HLINT ignore "Redundant do"        -}
+{- HLINT ignore "Reduce duplication"  -}
 
 runLoadSave :: Z.LoadSaveOptions -> IO ()
 runLoadSave opts = do
diff --git a/hw-eliasfano.cabal b/hw-eliasfano.cabal
--- a/hw-eliasfano.cabal
+++ b/hw-eliasfano.cabal
@@ -1,7 +1,7 @@
 cabal-version: 2.2
 
 name:                   hw-eliasfano
-version:                0.1.2.0
+version:                0.1.2.1
 synopsis:               Elias-Fano
 description:            Please see README.md
 category:               Data, Succinct Data Structures, Data Structures
@@ -9,10 +9,10 @@
 bug-reports:            https://github.com/haskell-works/hw-eliasfano/issues
 author:                 John Ky
 maintainer:             newhoggy@gmail.com
-copyright:              2016-2020 John Ky
+copyright:              2016-2021 John Ky
 license:                BSD-3-Clause
 license-file:           LICENSE
-tested-with:            GHC == 8.10.1, GHC == 8.8.3, GHC == 8.6.5, GHC == 8.4.4
+tested-with:            GHC == 9.2.2, GHC == 9.0.2, GHC == 8.10.7, GHC == 8.8.4, GHC == 8.6.5
 build-type:             Simple
 extra-source-files:     README.md
 
@@ -22,14 +22,14 @@
 
 common base                       { build-depends: base                       >= 4.11       && < 5      }
 
-common bytestring                 { build-depends: bytestring                 >= 0.10.8.2   && < 0.11   }
+common bytestring                 { build-depends: bytestring                 >= 0.10.8.2   && < 0.12   }
 common binary                     { build-depends: binary                     >= 0.8        && < 0.9    }
 common criterion                  { build-depends: criterion                  >= 1.5.5.0    && < 1.6    }
 common deepseq                    { build-depends: deepseq                    >= 1.4        && < 1.5    }
-common doctest                    { build-depends: doctest                    >= 0.16.2     && < 0.17   }
+common doctest                    { build-depends: doctest                    >= 0.16.2     && < 0.21   }
 common doctest-discover           { build-depends: doctest-discover           >= 0.2        && < 0.3    }
-common generic-lens               { build-depends: generic-lens               >= 1.2.0.1    && < 1.3    }
-common hedgehog                   { build-depends: hedgehog                   >= 0.6        && < 1.1    }
+common generic-lens               { build-depends: generic-lens               >= 2.2        && < 2.3    }
+common hedgehog                   { build-depends: hedgehog                   >= 0.6        && < 1.2    }
 common hspec                      { build-depends: hspec                      >= 2.7.1      && < 3      }
 common hw-bits                    { build-depends: hw-bits                    >= 0.7.0.6    && < 0.8    }
 common hw-hedgehog                { build-depends: hw-hedgehog                >= 0.1.0.3    && < 0.2    }
@@ -39,9 +39,9 @@
 common hw-prim                    { build-depends: hw-prim                    >= 0.6.2.26   && < 0.7    }
 common hw-rankselect              { build-depends: hw-rankselect              >= 0.13       && < 0.14   }
 common hw-rankselect-base         { build-depends: hw-rankselect-base         >= 0.3.2.1    && < 0.4    }
-common lens                       { build-depends: lens                       >= 4          && < 5      }
+common lens                       { build-depends: lens                       >= 4          && < 6      }
 common mmap                       { build-depends: mmap                       >= 0.5.9      && < 0.6    }
-common optparse-applicative       { build-depends: optparse-applicative       >= 0.14       && < 0.16   }
+common optparse-applicative       { build-depends: optparse-applicative       >= 0.14       && < 0.18   }
 common resourcet                  { build-depends: resourcet                  >= 1.2.2      && < 1.3    }
 common temporary-resourcet        { build-depends: temporary-resourcet        >= 0.1.0.1    && < 0.2    }
 common vector                     { build-depends: vector                     >= 0.12.0.3   && < 0.13   }
@@ -146,7 +146,7 @@
                       , hw-eliasfano
   default-language:     Haskell2010
   type:                 exitcode-stdio-1.0
-  ghc-options:          -threaded
+  ghc-options:          -threaded -rtsopts -with-rtsopts=-N
   main-is:              DoctestDriver.hs
   HS-Source-Dirs:       doctest
   build-tool-depends:   doctest-discover:doctest-discover
diff --git a/src/HaskellWorks/Data/EliasFano/Internal.hs b/src/HaskellWorks/Data/EliasFano/Internal.hs
--- a/src/HaskellWorks/Data/EliasFano/Internal.hs
+++ b/src/HaskellWorks/Data/EliasFano/Internal.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE DeriveGeneric     #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE TypeFamilies      #-}
 
diff --git a/test/HaskellWorks/Data/EliasFano/ReferenceSpec.hs b/test/HaskellWorks/Data/EliasFano/ReferenceSpec.hs
--- a/test/HaskellWorks/Data/EliasFano/ReferenceSpec.hs
+++ b/test/HaskellWorks/Data/EliasFano/ReferenceSpec.hs
@@ -11,12 +11,12 @@
 import qualified Hedgehog.Gen   as G
 import qualified Hedgehog.Range as R
 
-{-# ANN module ("HLint: ignore Redundant do" :: String) #-}
+{- HLINT ignore "Redundant do"        -}
 
 spec :: Spec
 spec = describe "HaskellWorks.Data.EliasFano.ReferenceSpec" $ do
   it "List to EliasFano" $ require $ withTests 1 $ property $ do
-    ws <- forAll $ pure $ [2, 3, 5, 7, 11, 13, 24]
+    ws <- forAll $ pure [2, 3, 5, 7, 11, 13, 24]
     let actual = fromWord64s ws
     let expected = EliasFano
           { efBucketBits  = [ True
diff --git a/test/HaskellWorks/Data/EliasFanoSpec.hs b/test/HaskellWorks/Data/EliasFanoSpec.hs
--- a/test/HaskellWorks/Data/EliasFanoSpec.hs
+++ b/test/HaskellWorks/Data/EliasFanoSpec.hs
@@ -17,12 +17,12 @@
 import qualified Hedgehog.Gen                                  as G
 import qualified Hedgehog.Range                                as R
 
-{-# ANN module ("HLint: ignore Redundant do" :: String) #-}
+{- HLINT ignore "Redundant do"        -}
 
 spec :: Spec
 spec = describe "HaskellWorks.Data.EliasFanoSpec" $ do
   it "List to EliasFano" $ requireTest $ do
-    ws <- forAll $ pure $ [2, 3, 5, 7, 11, 13, 24]
+    ws <- forAll $ pure [2, 3, 5, 7, 11, 13, 24]
     let actual = fromWord64s ws
     let expected = EliasFano
           { efBucketBits  = makeCsPoppy (DVS.fromList [4443])
@@ -86,7 +86,7 @@
     let expected = [2, 3, 5, 7, 11, 13, 24]
     actual === expected
   it "hiSegmentToWords" $ requireTest $ do
-    ws <- forAll $ pure $ [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144]
+    ws <- forAll $ pure [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144]
 
     filter (/= ' ') (bitShow (hiSegmentToWords ws)) === concat
       [ "01101010", "01000100", "00010000", "00001000", "00000000", "00100000", "00000000", "00000000"
