diff --git a/bisc.cabal b/bisc.cabal
index a0489c8..0f36b7f 100644
--- a/bisc.cabal
+++ b/bisc.cabal
@@ -39,4 +39,5 @@ executable bisc
                        data-default, bytestring,
                        optparse-applicative
   default-language:    Haskell2010
+  ghc-options:         -Wall
   extra-libraries:     snappy stdc++