diff --git a/number.cabal b/number.cabal
index 9ac01a7..1402cbe 100644
--- a/number.cabal
+++ b/number.cabal
@@ -30,7 +30,7 @@ library
                      Data.Number.Peano
    
   other-extensions:    TypeSynonymInstances, FlexibleInstances
-  build-depends:       base >=4.8
+  build-depends:       base >=4.8 && base < 5.0
   hs-source-dirs:      src
   default-language:    Haskell2010
   ghc-options:         -O2
\ No newline at end of file