diff --git a/xmonad.cabal b/xmonad.cabal
index c9ad677..4ec31e5 100644
--- a/xmonad.cabal
+++ b/xmonad.cabal
@@ -71,7 +71,7 @@ library
                    XMonad.StackSet
   other-modules:   Paths_xmonad
   hs-source-dirs:  src
-  build-depends:   base                  >= 4.6 && < 5
+  build-depends:   base                  >= 4.9 && < 5
                  , X11                   >= 1.8 && < 1.10
                  , containers
                  , data-default