diff --git a/bisc.cabal b/bisc.cabal
index a105ac5..75cd9b0 100644
--- a/bisc.cabal
+++ b/bisc.cabal
@@ -43,6 +43,6 @@ executable bisc
                        data-default, bytestring,
                        optparse-applicative
   default-language:    Haskell2010
-  ghc-options:         -Wall -Wno-name-shadowing
+  ghc-options:         -Wall -Wno-name-shadowing -O2
   if flag(static)
     extra-libraries:   snappy stdc++