diff --git a/show.cabal b/show.cabal
--- a/show.cabal
+++ b/show.cabal
@@ -1,5 +1,5 @@
 name:                show
-version:             0.3.3
+version:             0.3.4
 
 license:             GPL
 license-file:        LICENSE
@@ -22,10 +22,20 @@
 Cabal-Version:       >= 1.2
 tested-with:         GHC==6.8.2
 
+Flag Base4orNewer
+  Description: Adjusts the build dependencies depending on which version of Base is available.
+  -- Cabal checks if the configuration is possible, first
+  -- with this flag set to True and if not it tries with False
+
 library
    exposed-modules:     ShowQ, ShowFun, ShowIO, SimpleReflect
 
-   build-depends:       base >= 3 && < 5, random, QuickCheck<2, smallcheck>=0.4
+   build-depends:       random, QuickCheck<2, smallcheck>=0.4
+
+   if flag(Base4orNewer)
+     build-depends: base >= 4 && < 5, syb
+   else
+     build-depends: base >= 3 && < 4
 
    ghc-options:         -Wall
    ghc-prof-options:    -prof -auto-all