diff --git a/lib/Database/PostgreSQL/Opium.hs b/lib/Database/PostgreSQL/Opium.hs
index c9146a1..3444f5a 100644
--- a/lib/Database/PostgreSQL/Opium.hs
+++ b/lib/Database/PostgreSQL/Opium.hs
@@ -1,10 +1,6 @@
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE LambdaCase #-}
-{-# LANGUAGE KindSignatures #-}
-{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TypeApplications #-}
 
 module Database.PostgreSQL.Opium
diff --git a/opium.cabal b/opium.cabal
index c553f65..9a32840 100644
--- a/opium.cabal
+++ b/opium.cabal
@@ -52,7 +52,7 @@ build-type:         Simple
 -- extra-source-files:
 
 common warnings
-    ghc-options: -Wall
+    ghc-options: -Wall -Wextra
 
 library
     -- Import common warning flags.