diff --git a/utf8-string.cabal b/utf8-string.cabal
index c780ae506cda9ba3abd6acf771daf7277f9e9d7a..96e624fa41c17d61be5af5e8e5013d4eef5a2b65 100644
--- a/utf8-string.cabal
+++ b/utf8-string.cabal
@@ -36,4 +36,5 @@ library
 test-suite unit-tests
   type:               exitcode-stdio-1.0
   main-is:            tests/Tests.hs
-  build-depends:      HUnit >= 1.3 && < 1.4
+  build-depends:      base, HUnit >= 1.3 && < 1.4
+  default-language:   Haskell2010