Index: b/old-time.cabal
===================================================================
--- a/old-time.cabal
+++ b/old-time.cabal
@@ -53,7 +53,7 @@ Library
         HsTime.h
 
     build-depends:
-        base       >= 4.7 && < 4.9,
+        base       >= 4.7 && < 5,
         old-locale == 1.0.*
 
     ghc-options: -Wall
