diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,9 @@
+0.3.2
+
+* drop non-caninical definitions for Monad and Applicative, see
+https://github.com/Yuras/scanner/pull/15 and
+https://github.com/Yuras/scanner/pull/17
+
 0.3.1
 
 * support ghc-8.8
diff --git a/compat/Data/Either.hs b/compat/Data/Either.hs
deleted file mode 100644
--- a/compat/Data/Either.hs
+++ /dev/null
@@ -1,25 +0,0 @@
-{-# LANGUAGE PackageImports #-}
-{-# LANGUAGE CPP #-}
-
-module Data.Either
-(
-  module Export,
-#if MIN_VERSION_base(4,7,0)
-#else
-  isRight,
-  isLeft,
-#endif
-)
-where
-
-import "base" Data.Either as Export
-
-#if MIN_VERSION_base(4,7,0)
-#else
-isRight :: Either a b -> Bool
-isRight (Right _) = True
-isRight _ = False
-
-isLeft :: Either a b -> Bool
-isLeft = not . isRight
-#endif
diff --git a/compat/Prelude.hs b/compat/Prelude.hs
--- a/compat/Prelude.hs
+++ b/compat/Prelude.hs
@@ -14,11 +14,7 @@
 )
 where
 
-#if MIN_VERSION_base(4,6,0)
 import "base" Prelude as P
-#else
-import "base" Prelude as P hiding (catch)
-#endif
 
 #if MIN_VERSION_base(4,8,0)
 #else
diff --git a/lib/Scanner/Internal.hs b/lib/Scanner/Internal.hs
--- a/lib/Scanner/Internal.hs
+++ b/lib/Scanner/Internal.hs
@@ -46,21 +46,12 @@
 
 instance Applicative Scanner where
   {-# INLINE pure #-}
-  pure = return
+  pure a = Scanner $ \bs next ->
+    next bs a
   {-# INLINE (<*>) #-}
   (<*>) = ap
 
-  {-# INLINE (*>) #-}
-  (*>) = (>>)
-
-  {-# INLINE (<*) #-}
-  s1 <* s2 = s1 >>= \a -> s2 >> return a
-
 instance Monad Scanner where
-  {-# INLINE return #-}
-  return a = Scanner $ \bs next ->
-    next bs a
-
   {-# INLINE (>>=) #-}
   s1 >>= s2 = Scanner $ \bs next ->
     run s1 bs $ \bs' a ->
diff --git a/scanner.cabal b/scanner.cabal
--- a/scanner.cabal
+++ b/scanner.cabal
@@ -1,5 +1,5 @@
 name:                scanner
-version:             0.3.1
+version:             0.3.2
 synopsis:            Fast non-backtracking incremental combinator parsing for bytestrings
 homepage:            https://github.com/Yuras/scanner
 license:             BSD3
@@ -22,9 +22,8 @@
   exposed-modules:     Scanner
                        Scanner.Internal
   other-modules:       Prelude
-                       Data.Either
                        Scanner.OctetPredicates
-  build-depends:       base <5
+  build-depends:       base >=4.8 && <5
                      , fail
                      , bytestring
   hs-source-dirs:      lib, compat
@@ -40,7 +39,6 @@
                      , hspec
                      , scanner
   other-modules:       Prelude
-                       Data.Either
   default-language:    Haskell2010
 
 benchmark bench