diff --git a/binary.cabal b/binary.cabal
--- a/binary.cabal
+++ b/binary.cabal
@@ -1,5 +1,5 @@
 name:            binary
-version:         0.7.2.0
+version:         0.7.2.1
 license:         BSD3
 license-file:    LICENSE
 author:          Lennart Kolmodin <kolmodin@gmail.com>
diff --git a/src/Data/Binary/Get/Internal.hs b/src/Data/Binary/Get/Internal.hs
--- a/src/Data/Binary/Get/Internal.hs
+++ b/src/Data/Binary/Get/Internal.hs
@@ -248,12 +248,14 @@
       Done inp x -> C $ \_ ks -> ks inp x
       Fail _ _ -> pushBack bs >> g
       _ -> error "Binary: impossible"
+#if MIN_VERSION_base(4,2,0)
   some p = (:) <$> p <*> many p
   many p = do
     v <- (Just <$> p) <|> pure Nothing
     case v of
       Nothing -> pure []
       Just x -> (:) x <$> many p
+#endif
 
 -- | Run a decoder and keep track of all the input it consumes.
 -- Once it's finished, return the final decoder (always 'Done' or 'Fail'),