diff --git a/Data/BitSet.hs b/Data/BitSet.hs
--- a/Data/BitSet.hs
+++ b/Data/BitSet.hs
@@ -3,10 +3,10 @@
 import Control.Applicative
 import Control.Monad (guard)
 import Data.Bits
-import Data.List (concatMap)
 import Data.Maybe
 import Prelude ((==))
 import qualified Prelude as Base
+import Util
 import Util.Bits
 
 import Algebra
@@ -30,9 +30,9 @@
     mempty = zeroBits
 instance Bits a => Group (BitSet a) where invert = complement
 
-rangeInclusive :: (PartialOrd a, Bits a) => a -> a -> [a]
+rangeInclusive :: (PartialOrd a, Bits a, Alternative f) => a -> a -> f a
 rangeInclusive = \ x y -> go y x <* guard (x ≤ y)
-  where go y x = x : concatMap (go y) (setBit x <$> setBits (y .&¬ x))
+  where go y x = x <| altMap (go y ∘ setBit x) (setBits (y .&¬ x) :: [_])
 
 (.&?¬) :: (PartialOrd a, Bits a) => a -> a -> Maybe a
 a .&?¬ b = a .&¬ b <$ guard (b ≤ a)
diff --git a/alg.cabal b/alg.cabal
--- a/alg.cabal
+++ b/alg.cabal
@@ -1,5 +1,5 @@
 name:                alg
-version:             0.2.2.0
+version:             0.2.2.1
 synopsis:            Algebraic structures
 -- description:         
 license:             BSD3
@@ -13,6 +13,7 @@
 cabal-version:       >=1.10
 tested-with:         GHC ==8.0.2
                    , GHC ==8.2.2
+                   , GHC ==8.4.2
 
 library
   exposed-modules:     Algebra
@@ -21,14 +22,15 @@
   -- other-modules:       
   other-extensions:    
   build-depends:       base >=4.9 && <5
-                     , util >=0.1.5 && <0.2
+                     , util >=0.1.9 && <0.2
   -- hs-source-dirs:      
   default-language:    Haskell2010
   default-extensions:  NoImplicitPrelude
                      , LambdaCase
                      , EmptyCase
+                     , PartialTypeSignatures
                      , TypeOperators
                      , ConstraintKinds
                      , PolyKinds
                      , GeneralizedNewtypeDeriving
-  ghc-options:         -Wall
+  ghc-options:         -Wall -Wno-partial-type-signatures