diff --git a/utf8-string.cabal b/utf8-string.cabal
index 06d21af55f011d2422b8aef85b0947504937547c..fa6160a131b3fcc7ce0da834c9e7c349d978ab84 100644
--- a/utf8-string.cabal
+++ b/utf8-string.cabal
@@ -15,6 +15,7 @@ Build-type:         Simple
 cabal-version:      >= 1.2
 
 flag bytestring-in-base
+  default: False
 
 library
   Ghc-options:        -W -O2