diff --git a/RomanNum.cabal b/RomanNum.cabal
index f9a2e0d..abfad60 100644
--- a/RomanNum.cabal
+++ b/RomanNum.cabal
@@ -19,7 +19,7 @@ library
   exposed-modules:     Data.RomanNum
   -- other-modules:
   -- other-extensions:
-  build-depends:       base ^>=4.11.1.0
+  build-depends:       base <= 4.13
                      , containers
   hs-source-dirs:      src
   default-language:    Haskell2010