diff --git a/addressbook.cabal b/addressbook.cabal
index 7f70620..1d10838 100644
--- a/addressbook.cabal
+++ b/addressbook.cabal
@@ -38,6 +38,7 @@ library
                      , containers
   hs-source-dirs:      src
   default-language:    Haskell2010
+  ghc-options:         -Wall
 
 executable addressbook
   main-is:             Main.hs
@@ -45,8 +46,10 @@ executable addressbook
   -- other-extensions:
   build-depends:       base ^>=4.13.0.0, addressbook
                      , optparse-applicative
+                     , text
   hs-source-dirs:      app
   default-language:    Haskell2010
+  ghc-options:         -Wall
 
 test-suite addressbook-test
   default-language:    Haskell2010
@@ -70,3 +73,4 @@ test-suite addressbook-test
                      , vector
                      , conduit
                      , conduit-extra
+  ghc-options:         -Wall