diff --git a/Text/Show/ByteString.hs b/Text/Show/ByteString.hs
--- a/Text/Show/ByteString.hs
+++ b/Text/Show/ByteString.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE TypeSynonymInstances, FlexibleInstances #-}
 
 -- ---------------------------------------------------------------------------
 -- |
diff --git a/bytestring-show.cabal b/bytestring-show.cabal
--- a/bytestring-show.cabal
+++ b/bytestring-show.cabal
@@ -1,5 +1,5 @@
 name:              bytestring-show
-version:           0.3.4
+version:           0.3.5
 license:           BSD3
 license-file:      LICENSE
 author:            Dan Doel
@@ -25,14 +25,19 @@
         Text.Show.ByteString.Integer
 
     extensions:
-        UnboxedTuples, MagicHash, BangPatterns, TypeSynonymInstances, CPP
+        UnboxedTuples,
+        MagicHash,
+        BangPatterns,
+        TypeSynonymInstances,
+        CPP,
+        FlexibleInstances
 
     ghc-options:
         -O2 -Wall
 
     if impl(ghc >= 6.11)
         cpp-options: -DINTEGER_GMP
-        build-depends: integer-gmp >= 0.2 && < 0.3
+        build-depends: integer-gmp >= 0.2 && < 0.4
 
     if impl(ghc >= 6.9) && impl(ghc < 6.11)
         cpp-options: -DINTEGER_GMP